Tüm alıştırma soruları

2789 soru

Soru 2521Soru

In right triangle ABCABC, the measure of angle CC is 9090^\circ. If cos(A)=3sin(A)\cos(A) = 3\sin(A), what is the value of tan(B)\tan(B)?

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Cevap: 3

Cevap

The correct answer is 33.
Because angle CC is 9090^\circ in right triangle ABCABC, the acute angles AA and BB are complementary (A+B=90A + B = 90^\circ). By the co-function identities, sin(B)=cos(A)\sin(B) = \cos(A) and cos(B)=sin(A)\cos(B) = \sin(A). The tangent of BB is defined as tan(B)=sin(B)cos(B)\tan(B) = \frac{\sin(B)}{\cos(B)}. Substituting the co-function identities gives tan(B)=cos(A)sin(A)\tan(B) = \frac{\cos(A)}{\sin(A)}. Since we are given that cos(A)=3sin(A)\cos(A) = 3\sin(A), we substitute this expression into the numerator to get tan(B)=3sin(A)sin(A)=3\tan(B) = \frac{3\sin(A)}{\sin(A)} = 3.

Adım Adım Çözüm

1
Determine the relationship between the acute angles in right triangle ABCABC.
sin(B)=cos(A)\sin(B) = \cos(A) and cos(B)=sin(A)\cos(B) = \sin(A)
Since angle CC is 9090^\circ, the other two angles AA and BB must sum to 9090^\circ (they are complementary angles).
2
Express tan(B)\tan(B) in terms of the trigonometric ratios of angle AA.
tan(B)=cos(A)sin(A)\tan(B) = \frac{\cos(A)}{\sin(A)}
By definition, the tangent of angle BB is the ratio of its sine to its cosine, which yields cos(A)sin(A)\frac{\cos(A)}{\sin(A)} after substituting the complementary angle relations.
3
Substitute the given relation cos(A)=3sin(A)\cos(A) = 3\sin(A) into the expression for tan(B)\tan(B).
tan(B)=3sin(A)sin(A)\tan(B) = \frac{3\sin(A)}{\sin(A)}
Substituting the value of cos(A)\cos(A) allows us to simplify the fraction by expressing both terms with sin(A)\sin(A).
4
Simplify the fraction to get the final numerical value.
tan(B)=3\tan(B) = 3
The term sin(A)\sin(A) cancels out from the numerator and denominator since AA is an acute angle and sin(A)0\sin(A) \neq 0.

Anahtar Kavram

Co-function identities and trigonometric definitions in a right triangle.

Alternatif Yöntem

Alternatively, construct a right triangle where the side opposite to angle AA has length 11. Since cos(A)=3sin(A)\cos(A) = 3\sin(A), the ratio of the adjacent side to the hypotenuse is 33 times the ratio of the opposite side to the hypotenuse, meaning the side adjacent to angle AA must have length 33. Because angle BB is the complement of angle AA, the side opposite to angle BB is the side adjacent to angle AA (which is 33), and the side adjacent to angle BB is the side opposite to angle AA (which is 11). Therefore, tan(B)=oppositeadjacent=31=3\tan(B) = \frac{\text{opposite}}{\text{adjacent}} = \frac{3}{1} = 3.
Tahmini Süre:1m 30s
Soru 2522Soru

Which word completes the text with the most logical and precise word?

Aşağıdaki boşlukları doldurun

For many years, linguists assumed that the grammatical structures of signed languages were fundamentally simpler than those of spoken languages, viewing them as mere systems of gestural pantomime. However, pioneering research in the mid-twentieth century demonstrated that signed languages possess complex, rule-governed phonological and syntactic systems comparable to any spoken tongue. This body of research effectively the misconception that signed languages are primitive communication systems.
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Cevap

The blank is correctly completed by a word such as 'dispelled', 'debunked', or 'refuted', which indicates that the scientific research disproved or corrected the false assumption about signed languages.
The correct word must mean to disprove or eliminate a false belief, as the passage describes how newer research showed signed languages have complex structures, contradicting the previous view. Words like 'dispelled', 'debunked', and 'refuted' logically and precisely complete this meaning.

Adım Adım Çözüm

1
Analyze the context and contrast clues in the passage.
The passage begins with an old assumption ('linguists assumed that... signed languages were fundamentally simpler') and introduces a contrast with 'However', describing newer research showing they possess complex systems.
Identifying the transition from the old assumption to the new findings is key to understanding the logical flow of the text.
2
Determine the relationship between the new research and the old misconception.
Since the research proved signed languages are complex, it must have disproved or eliminated the misconception that they are primitive.
This establishes that the correct word must mean to disprove, reject, or eliminate a false belief.

Anahtar Kavram

Selecting words that precisely fit the logical context of a passage, especially when dealing with contrast and shift in scientific consensus.
Soru 2523Soru

Deep-sea hydrothermal vent ecosystems are typically characterized by their reliance on chemosynthesis, where microbes convert chemical energy from vent fluids into organic matter. However, marine biologist Marcus Vance has identified several vent sites where photosynthetic microbes utilize geothermal radiation—the faint infrared glow emitted by superheated water��to perform a form of non-solar photosynthesis. This discovery challenges the long-held paradigm that photosynthesis is strictly dependent on sunlight reaching the photic zone. Consequently, Vance's research suggests that primary production in the deep ocean may be more diverse and widespread than previously assumed, requiring a revision of ecological models for aphotic environments.

Which choice best describes the function of the underlined sentence in the text as a whole?

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Cevap: It introduces a specific finding that challenges a prevailing assumption about the types of biological processes occurring in deep-sea environments.

Cevap

The choice that states the underlined sentence introduces a specific finding that challenges a prevailing assumption about the types of biological processes occurring in deep-sea environments.
The correct answer is correct because the passage begins by stating a common characteristic of hydrothermal vents (their reliance on chemosynthesis). The underlined sentence introduces Marcus Vance's discovery of photosynthetic microbes at these vents, which utilize geothermal radiation rather than sunlight. This finding directly challenges the general assumption that photosynthesis cannot occur in the deep, lightless ocean. Therefore, the sentence functions to introduce a discovery that challenges a prevailing assumption about biological processes in this environment.

Adım Adım Çözüm

1
Analyze the context before the underlined sentence.
The opening sentence establishes a typical baseline or prevailing assumption: that deep-sea hydrothermal vent ecosystems are defined by their reliance on chemosynthesis.
To understand how the underlined sentence functions, we must first understand the context it responds to.
2
Analyze the content and function of the underlined sentence itself.
The underlined sentence introduces a counter-example or new finding: the discovery of microbes at vent sites performing non-solar photosynthesis using geothermal radiation.
This step determines the direct meaning and immediate logical role of the sentence.
3
Analyze the context after the underlined sentence and determine the relationship between the parts.
The subsequent sentences explain that this discovery 'challenges the long-held paradigm' and suggest revisions to current ecological models. Therefore, the underlined sentence serves to introduce the specific finding that drives this shift away from the traditional assumption mentioned at the start.
This final step integrates the part into the whole structure of the text to identify its rhetorical purpose.

Anahtar Kavram

Analyzing how a specific sentence or part of a text contributes to the development of the author's overall argument or explanation.
Tahmini Süre:1m 30s
Soru 2524Soru

In rectangle ABCDABCD, the length of side ABAB is 1212 and the length of side BCBC is 99. Point PP lies on the diagonal ACAC such that AP=13ACAP = \frac{1}{3} AC. What is the area of triangle BPDBPD?

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Cevap: 18

Cevap

18
The correct answer is 18. The area of the right triangle ABDABD is half of the area of rectangle ABCDABCD, which is 12×92=54\frac{12 \times 9}{2} = 54. Since point PP lies on diagonal ACAC such that AP=13ACAP = \frac{1}{3} AC, triangle ABPABP has a base of APAP along line ACAC and shares vertex BB with triangle ABCABC. Thus, its area is 13\frac{1}{3} of the area of triangle ABCABC, which is 543=18\frac{54}{3} = 18. Similarly, triangle ADPADP shares vertex DD with triangle ADCADC and has base APAP, so its area is 13\frac{1}{3} of the area of triangle ADCADC, which is 543=18\frac{54}{3} = 18. Because AP=13AC<12ACAP = \frac{1}{3} AC < \frac{1}{2} AC, point PP lies inside triangle ABDABD. Therefore, the area of triangle BPDBPD is the area of triangle ABDABD minus the areas of triangles ABPABP and ADPADP, which is 541818=1854 - 18 - 18 = 18.

Adım Adım Çözüm

1
Calculate the area of triangle ABDABD.
Area(ABD)=12×92=54\text{Area}(\triangle ABD) = \frac{12 \times 9}{2} = 54
The diagonal BDBD divides the rectangle ABCDABCD into two congruent right triangles, each with an area equal to half of the rectangle's total area.
2
Find the areas of triangles ABPABP and ADPADP using the ratio of APAP to ACAC.
Area(ABP)=13×Area(ABC)=18\text{Area}(\triangle ABP) = \frac{1}{3} \times \text{Area}(\triangle ABC) = 18 and Area(ADP)=13×Area(ADC)=18\text{Area}(\triangle ADP) = \frac{1}{3} \times \text{Area}(\triangle ADC) = 18.
Triangles ABPABP and ABCABC share the same altitude from vertex BB to the line containing diagonal ACAC. Therefore, the ratio of their areas is equal to the ratio of their bases, which is APAC=13\frac{AP}{AC} = \frac{1}{3}. The same logic applies to triangles ADPADP and ADCADC with vertex DD.
3
Subtract the areas of triangles ABPABP and ADPADP from the area of triangle ABDABD to find the area of triangle BPDBPD.
Area(BPD)=541818=18\text{Area}(\triangle BPD) = 54 - 18 - 18 = 18
Since AP=13ACAP = \frac{1}{3} AC, which is less than half the length of the diagonal, point PP lies strictly within the interior of triangle ABDABD. Thus, the area of triangle ABDABD is partitioned into the areas of triangles ABPABP, ADPADP, and BPDBPD.

Anahtar Kavram

Partitioning the area of a polygon and using the ratio of bases for triangles sharing a vertex to compute sub-areas.

Alternatif Yöntem

Alternatively, place the rectangle in a coordinate system with BB at the origin (0,0)(0,0), CC at (12,0)(12,0), AA at (0,9)(0,9), and DD at (12,9)(12,9). The coordinates of point PP on diagonal ACAC (from (0,9)(0,9) to (12,0)(12,0)) at one-third of the distance from AA to CC are x=0+13(120)=4x = 0 + \frac{1}{3}(12 - 0) = 4 and y=9+13(09)=6y = 9 + \frac{1}{3}(0 - 9) = 6. The area of triangle BPDBPD with vertices B(0,0)B(0,0), P(4,6)P(4,6), and D(12,9)D(12,9) can be found using the shoelace formula: Area=120(69)+4(90)+12(06)=123672=18\text{Area} = \frac{1}{2} |0(6 - 9) + 4(9 - 0) + 12(0 - 6)| = \frac{1}{2} |36 - 72| = 18.
Tahmini Süre:2m 0s
Soru 2525Soru

While preparing a presentation on zoology, a student took the following notes:
* Ethology is the scientific study of animal behavior, particularly under natural conditions.
* It is considered a sub-discipline of zoology.
* The field was formalized by biologists Nikolaas Tinbergen and Konrad Lorenz.
* Ethologists study behaviors such as communication, mating rituals, and social interactions.
* A primary goal of ethology is understanding how behaviors adapt and evolve to assist in animal survival.

The student wants to introduce the field of ethology and define the term. Which choice best uses information from the notes to achieve this goal?

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Cevap: Ethology is a sub-discipline of zoology defined as the scientific study of animal behavior, particularly under natural conditions.

Cevap

The statement defining ethology as a sub-discipline of zoology focused on the scientific study of animal behavior under natural conditions.
The correct option successfully introduces the field of ethology and defines it by stating that it is a sub-discipline of zoology and explaining that it is the scientific study of animal behavior under natural conditions. This synthesizes the relevant introductory and definitional information from the notes without focusing on irrelevant details like the founders or specific behaviors studied.

Adım Adım Çözüm

1
Analyze the student's specific goal in the prompt.
The goal is to write a sentence that introduces the field of ethology and defines the term.
Identifying the goal helps filter out notes and choices that focus on history, applications, or secondary details rather than definition.
2
Evaluate the notes to identify which facts introduce the field and define the term.
The first note provides the definition (the scientific study of animal behavior, particularly under natural conditions) and the second note introduces its classification (a sub-discipline of zoology).
These two notes contain the core definition and introductory context needed to meet the prompt's requirements.
3
Compare the choices against the identified notes to find the one that combines introduction and definition.
The option stating that ethology is a sub-discipline of zoology defined as the scientific study of animal behavior under natural conditions is the only choice that directly defines the term and introduces the field.
The other choices focus on the historical founders, specific behaviors studied, or the field's evolutionary goals, thereby neglecting the primary task of defining the term.

Anahtar Kavram

Rhetorical Synthesis: Introduction and Definition
Tahmini Süre:1m 0s
Soru 2526Soru

The table below shows several values of the function ff.

xxf(x)f(x)
5-51212
3-32-2
1-144
331818

The function gg is defined by g(x)=12f(x+4)+3g(x) = \frac{1}{2}f(x + 4) + 3. What is the value of g(5)g(-5)?

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Cevap: 5

Cevap

The correct answer is 5.
To find the value of g(5)g(-5), substitute 5-5 for xx in the definition of g(x)g(x), which gives g(5)=12f(5+4)+3=12f(1)+3g(-5) = \frac{1}{2}f(-5 + 4) + 3 = \frac{1}{2}f(-1) + 3. According to the table, f(1)=4f(-1) = 4. Substituting this value into the expression yields g(5)=12(4)+3=2+3=5g(-5) = \frac{1}{2}(4) + 3 = 2 + 3 = 5.

Adım Adım Çözüm

1
Substitute the input value into the function definition.
g(5)=12f(5+4)+3=12f(1)+3g(-5) = \frac{1}{2}f(-5 + 4) + 3 = \frac{1}{2}f(-1) + 3
To evaluate g(5)g(-5), replace all occurrences of xx with 5-5 in the definition of g(x)g(x).
2
Find the value of f(1)f(-1) from the table.
f(1)=4f(-1) = 4
The table provides specific input-output pairs for the function ff. When the input is 1-1, the output is 44.
3
Calculate the final value.
g(5)=2+3=5g(-5) = 2 + 3 = 5
Substitute 44 for f(1)f(-1) in the expression and simplify the terms.

Anahtar Kavram

Evaluating transformed functions using tabular data and applying horizontal translations, vertical compressions, and vertical translations.
Soru 2527Soru

In the late fourth millennium BCE, administrative practices in Mesopotamian city-states underwent a critical transformation due to expanding trade networks. Initially, accounting relied on individual clay tokens of various shapes representing specific quantities of goods. As transactions grew more complex, administrators began impressing these tokens directly into clay envelopes, and eventually, drawing representations of the tokens on flat clay tablets instead. This transition marked the birth of proto-cuneiform writing, shifting human communication from three-dimensional object-based recordkeeping to two-dimensional symbolic notation. Consequently, this technological shift laid the foundation for the development of fully abstract writing systems capable of recording spoken language.

Which choice best describes the function of the underlined sentence in the text as a whole?

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Cevap: It identifies the broader historical significance of the administrative change detailed in the preceding sentences.

Cevap

The correct option identifies the broader historical significance of the administrative change detailed in the preceding sentences.
The correct option accurately captures the relationship between the underlined sentence and the preceding sentences. The passage first describes how Mesopotamian administrators shifted from using physical, three-dimensional clay tokens to flat clay tablets with drawings. The underlined sentence then explicitly conceptualizes this change, explaining that it represents a shift from object-based to symbolic recordkeeping and marks the origin of proto-cuneiform. This explains the broader significance of the transition.

Adım Adım Çözüm

1
Analyze the context surrounding the underlined sentence.
The sentences before the underlined text describe an evolution in accounting tools: from three-dimensional clay tokens to drawings on two-dimensional flat clay tablets.
Understanding the preceding text is necessary to determine what transition is being referred to in the underlined portion.
2
Examine the role of the underlined sentence itself.
The underlined sentence defines this shift as the birth of proto-cuneiform writing and characterizes it as moving from object-based to symbolic communication.
This step reveals the function of the sentence: it frames the transition in terms of its conceptual and historical importance.
3
Assess how this sentence connects to the final sentence.
The final sentence discusses the consequence of this transition: it laid the groundwork for abstract systems that could record spoken language.
Analyzing the follow-up sentence confirms that the underlined sentence functions to conceptualize the historical pivot before its long-term effects are stated.

Anahtar Kavram

Identifying the rhetorical function of a specific sentence or part within the context of a short academic passage.
Tahmini Süre:1m 30s
Soru 2528Soru

In right triangle RSTRST, the measure of angle TT is 9090^\circ and the length of the hypotenuse RSRS is 1010. If tan(R)+tan(S)=52\tan(R) + \tan(S) = \frac{5}{2}, what is the area of triangle RSTRST?

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Cevap: 20

Cevap

20
Let the lengths of the legs of right triangle RSTRST be RT=xRT = x and ST=yST = y. The tangent ratios are tan(R)=yx\tan(R) = \frac{y}{x} and tan(S)=xy\tan(S) = \frac{x}{y}. Substituting these into the given equation gives yx+xy=52\frac{y}{x} + \frac{x}{y} = \frac{5}{2}, which simplifies to x2+y2xy=52\frac{x^2 + y^2}{xy} = \frac{5}{2}. By the Pythagorean theorem, x2+y2=102=100x^2 + y^2 = 10^2 = 100. Thus, 100xy=52\frac{100}{xy} = \frac{5}{2}, which solves to xy=40xy = 40. The area of the triangle is 12xy=12(40)=20\frac{1}{2}xy = \frac{1}{2}(40) = 20.

Adım Adım Çözüm

1
Express the tangent of angles RR and SS in terms of the leg lengths RTRT and STST.
tan(R)=STRT\tan(R) = \frac{ST}{RT} and tan(S)=RTST\tan(S) = \frac{RT}{ST}.
By definition, the tangent of an acute angle in a right triangle is the ratio of the opposite leg to the adjacent leg.
2
Substitute these expressions into the given equation and simplify using the Pythagorean theorem.
STRT+RTST=ST2+RT2RTST=100RTST=52\frac{ST}{RT} + \frac{RT}{ST} = \frac{ST^2 + RT^2}{RT \cdot ST} = \frac{100}{RT \cdot ST} = \frac{5}{2}.
Finding a common denominator yields the sum of the squares of the legs in the numerator, which equals the square of the hypotenuse (RS2=102=100RS^2 = 10^2 = 100).
3
Solve for the product of the legs RTSTRT \cdot ST and calculate the area of the triangle.
RTST=40RT \cdot ST = 40, so Area=12(RTST)=12(40)=20\text{Area} = \frac{1}{2}(RT \cdot ST) = \frac{1}{2}(40) = 20.
The area of a right triangle is half the product of its perpendicular legs.

Anahtar Kavram

Using trigonometric ratios, complementary angles, and the Pythagorean theorem to calculate the area of a right triangle.
Soru 2529Soru

In the field of sociolinguistics, researchers have documented that speakers frequently alter their speech patterns depending on their social environment, a phenomenon known as style-shifting. ________, a bilingual individual might utilize informal slang when conversing with peers but adopt formal grammar and vocabulary during a job interview.

Which choice completes the text with the most logical transition?

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Cevap: For instance,

Cevap

For instance,
The transition 'For instance' is correct because the second sentence serves as a concrete example of style-shifting, the general concept described in the first sentence.

Adım Adım Çözüm

1
Analyze the relationship between the two sentences.
The first sentence defines 'style-shifting' as speakers altering speech patterns based on social environments. The second sentence provides a specific case of a bilingual individual changing speech patterns between peers and a job interview.
Understanding how the ideas connect is necessary to choose the correct transition.
2
Identify the logical category of the relationship.
The relationship is exemplification, as the second sentence presents a concrete example of the general concept of style-shifting.
Matching the conceptual link to transition categories narrows down the choices.
3
Select the transition word that expresses this relationship.
'For instance' correctly signals that the second sentence is an example of the first.
This completes the text logically.

Anahtar Kavram

Transitions: Elaboration and Exemplification
Tahmini Süre:1m 0s
Soru 2530Soru

Which word completes the text with the most logical and precise word or phrase?

Aşağıdaki boşlukları doldurun

In translation studies, early theories often emphasized literal equivalence, demanding that a translation match the source text word-for-word. Modern translators, however, argue that such a rigid approach is often because it fails to capture the cultural nuances and idiomatic expressions of the target language.
Cevabı ve açıklamayı göster

Cevap

counterproductive (or synonyms like ineffective, impractical, inadequate, flawed, unsuccessful, self-defeating)
The sentence contrasts early word-for-word translation theories with modern views. The conjunction 'however' and the explanatory clause 'because it fails to capture...' indicate that modern translators view the rigid approach negatively. Thus, the blank must be filled by a word meaning ineffective, counterproductive, or inadequate.

Adım Adım Çözüm

1
Identify the transition and tone clues in the sentence.
The word 'however' indicates a contrast with the early emphasis on literal equivalence, while the phrase 'fails to capture... nuances' indicates that the missing word must have a negative connotation.
To determine whether the blank requires a word with a positive, negative, or neutral charge.
2
Analyze the relationship between the rigid approach and the failure to capture nuances.
Because the rigid approach fails to achieve the goal of conveying cultural and idiomatic meaning, the approach itself is not useful or is harmful to the translation process.
To define the precise semantic meaning required for the blank.
3
Select a high-utility academic word that matches the required meaning.
Words like 'counterproductive' or 'ineffective' fit the context perfectly by expressing that a word-for-word translation strategy defeats its own purpose.
To complete the sentence with a logically and grammatically precise term.

Anahtar Kavram

Words in Context: High-Utility Vocabulary
Tahmini Süre:1m 0s
Soru 2531Soru

In right triangle ABCABC, the hypotenuse ACAC has length 2525, and leg ABAB has length 2020. What is the length of leg BCBC?

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Cevap: 15

Cevap

15
For any right triangle, the sum of the squares of the legs is equal to the square of the hypotenuse (a2+b2=c2a^2 + b^2 = c^2). In right triangle ABCABC, the hypotenuse is AC=25AC = 25 and one of the legs is AB=20AB = 20. Substituting these values into the theorem gives 202+BC2=25220^2 + BC^2 = 25^2, which simplifies to 400+BC2=625400 + BC^2 = 625. Subtracting 400400 from both sides results in BC2=225BC^2 = 225. Taking the square root of both sides gives the length of leg BCBC as 1515.

Adım Adım Çözüm

1
Set up the Pythagorean theorem equation for the right triangle.
AB2+BC2=AC2AB^2 + BC^2 = AC^2
The Pythagorean theorem relates the lengths of the legs and the hypotenuse of any right triangle.
2
Substitute the known lengths of side ABAB and hypotenuse ACAC.
202+BC2=25220^2 + BC^2 = 25^2
We plug in 2020 for leg ABAB and 2525 for hypotenuse ACAC.
3
Evaluate the squared terms.
400+BC2=625400 + BC^2 = 625
Squaring 2020 gives 400400, and squaring 2525 gives 625625.
4
Isolate the variable term BC2BC^2.
BC2=225BC^2 = 225
Subtracting 400400 from both sides of the equation yields 225225.
5
Find the length of side BCBC.
BC=15BC = 15
Taking the square root of 225225 gives the positive length of leg BCBC.

Anahtar Kavram

Applying the Pythagorean theorem to calculate a missing leg length of a right triangle when the hypotenuse and one leg length are given.
Soru 2532Soru

An angle has a measure of 7272^\circ. What is the measure of this angle in radians?

Cevabı ve açıklamayı göster

Cevap: 2π5\frac{2\pi}{5}

Cevap

The correct answer is 2π5\frac{2\pi}{5} radians.
To convert an angle from degrees to radians, multiply the degree measure by π180\frac{\pi}{180}. Doing so for 7272^\circ yields 72π180\frac{72\pi}{180}. Dividing the numerator and denominator by their greatest common divisor, 36, simplifies the fraction to 2π5\frac{2\pi}{5}.

Adım Adım Çözüm

1
Set up the conversion from degrees to radians by multiplying the given degree measure by π180\frac{\pi}{180}.
θ=72×π180=72π180\theta = 72 \times \frac{\pi}{180} = \frac{72\pi}{180}
The conversion factor from degrees to radians is π radians180\frac{\pi \text{ radians}}{180^\circ}.
2
Simplify the fraction by dividing the numerator and the denominator by their greatest common divisor, 36.
72÷36180÷36π=2π5\frac{72 \div 36}{180 \div 36}\pi = \frac{2\pi}{5}
Simplifying the fraction expresses the angle in standard reduced radian form.

Anahtar Kavram

Converting degrees to radians
Soru 2533Soru

The graph of the polynomial function ff in the xyxy-plane is tangent to the xx-axis at (1,0)(1, 0) and crosses the xx-axis only at (2,0)(-2, 0) and (4,0)(4, 0). If the yy-intercept of the graph of ff is (0,8)(0, 8), what is the value of f(1)f(-1)?

Cevabı ve açıklamayı göster

Cevap: 20

Cevap

20
The graph of the polynomial function is tangent to the xx-axis at (1,0)(1, 0) and crosses it at (2,0)(-2, 0) and (4,0)(4, 0). This means x=1x = 1 is a root with multiplicity 2, while x=2x = -2 and x=4x = 4 are roots with multiplicity 1. Thus, we can write the function in the form f(x)=a(x+2)(x1)2(x4)f(x) = a(x + 2)(x - 1)^2(x - 4). Substituting the yy-intercept (0,8)(0, 8) gives 8=a(0+2)(01)2(04)    8=8a    a=18 = a(0 + 2)(0 - 1)^2(0 - 4) \implies 8 = -8a \implies a = -1. Substituting a=1a = -1 back into the formula yields f(x)=(x+2)(x1)2(x4)f(x) = -(x + 2)(x - 1)^2(x - 4). Evaluating the function at x=1x = -1 gives f(1)=(1+2)(11)2(14)=(1)(4)(5)=20f(-1) = -(-1 + 2)(-1 - 1)^2(-1 - 4) = -(1)(4)(-5) = 20. Therefore, the correct value is 20.

Adım Adım Çözüm

1
Determine the factored form of the polynomial from its x-intercepts and multiplicities.
f(x)=a(x+2)(x1)2(x4)f(x) = a(x + 2)(x - 1)^2(x - 4)
Since the graph is tangent to the xx-axis at (1,0)(1, 0), the root x=1x = 1 has a multiplicity of 2, corresponding to the factor (x1)2(x - 1)^2. Since it crosses the xx-axis at (2,0)(-2, 0) and (4,0)(4, 0), these roots have a multiplicity of 1, corresponding to the factors (x+2)(x + 2) and (x4)(x - 4).
2
Use the y-intercept to find the constant coefficient aa.
a=1a = -1
The yy-intercept is (0,8)(0, 8), so substituting x=0x = 0 into the equation gives 8=a(0+2)(01)2(04)    8=8a    a=18 = a(0 + 2)(0 - 1)^2(0 - 4) \implies 8 = -8a \implies a = -1.
3
Substitute the value of aa back into the function and evaluate f(1)f(-1).
f(1)=20f(-1) = 20
Substituting a=1a = -1 gives f(x)=(x+2)(x1)2(x4)f(x) = -(x + 2)(x - 1)^2(x - 4). Evaluating at x=1x = -1 yields f(1)=(1+2)(11)2(14)=(1)(2)2(5)=(1)(4)(5)=20f(-1) = -(-1 + 2)(-1 - 1)^2(-1 - 4) = -(1)(-2)^2(-5) = -(1)(4)(-5) = 20.

Anahtar Kavram

Determining a polynomial function's equation from its graphical features (intercepts and tangencies) and evaluating it at a point.
Tahmini Süre:1m 30s
Soru 2534Soru

Scholars studying the evolution of Indo-European languages have traditionally relied on comparative reconstruction. Recently, researchers applied evolutionary biology models to vocabulary databases, treating words as traits that mutate over time. These models revealed that high-frequency basic vocabulary items, such as pronouns, mutate at a much slower rate than low-frequency terms, such as words for specific tools. Because high-frequency words are reinforced daily within a speech community, they remain highly resistant to replacement, whereas low-frequency words are more susceptible to borrowing during cultural contact. Thus, in an ancient language that experienced intense and prolonged contact with neighboring tongues, ______

Which choice most logically completes the text?

Cevabı ve açıklamayı göster

Cevap: its basic vocabulary would remain largely stable even if many of its terms for tools were replaced by borrowed words.

Cevap

The language's basic vocabulary would remain largely stable even if many of its terms for tools were replaced by borrowed words.
The passage establishes that basic vocabulary items (such as pronouns) mutate slowly and are highly resistant to replacement, while low-frequency words (such as words for tools) are more susceptible to borrowing during cultural contact. Therefore, in a language experiencing intense cultural contact, the basic vocabulary is expected to remain stable even if low-frequency words are replaced by borrowed words.

Adım Adım Çözüm

1
Analyze the premises regarding vocabulary mutation and frequency.
High-frequency basic vocabulary (such as pronouns) mutates slowly and resists replacement, whereas low-frequency vocabulary (such as terms for tools) mutates faster and is easily borrowed.
To establish the rules governing vocabulary change given in the text.
2
Analyze the scenario of intense cultural contact.
Cultural contact increases borrowing, which primarily affects low-frequency words because basic vocabulary is reinforced daily and is resistant to replacement.
To apply the established rules to the specific condition of cultural contact.
3
Synthesize the findings to complete the blank.
Under intense contact, the basic vocabulary remains stable, while low-frequency terms undergo borrowing and replacement.
To identify the choice that logically completes the text based on the premises.

Anahtar Kavram

Logical Inferences
Soru 2535Soru

In a study of the history of technology and metallurgy, researchers analyzed copper artifacts from the Bronze Age in the Aegean region. It was previously assumed that smiths preferred copper sourced from nearby local mines due to transportation difficulties. However, chemical analysis of the isotopic signatures of trace lead impurities in these artifacts reveals that a substantial portion of the bronze objects found in coastal settlements matches copper deposits from distant western Mediterranean islands, whereas artifacts found in inland settlements match local mainland deposits. This pattern remained consistent even during periods of regional conflict that disrupted overland trade routes. Which choice most logically completes the text?

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Cevap: maritime transportation networks allowed coastal settlements to maintain their copper supply lines from distant sources even when land-based trade was disrupted.

Cevap

The correct answer is the statement that maritime transportation networks allowed coastal settlements to maintain their copper supply lines from distant sources even when land-based trade was disrupted.
The passage states that copper artifacts in coastal settlements matched distant island deposits, while those in inland settlements matched local mainland deposits, and that this pattern was unaffected by conflicts disrupting overland trade. This directly supports the conclusion that the maritime transport networks supplying the coastal settlements functioned independently of the disrupted overland routes.

Adım Adım Çözüm

1
Analyze the findings presented in the passage regarding copper artifacts.
Coastal settlements used copper from distant western Mediterranean islands, while inland settlements used local mainland copper.
To identify the baseline distribution of copper sources before considering the impact of conflict.
2
Evaluate the effect of regional conflicts on the trade routes.
Conflicts disrupted overland trade routes, but the pattern of coastal settlements sourcing copper from distant islands remained consistent.
To determine which transport routes were affected and which remained functional.
3
Infer the logical conclusion of these persistent patterns.
Since overland routes were disrupted but coastal-island sourcing was not, the maritime networks supplying the coasts must have operated independently of the overland routes.
To resolve the prompt by selecting the option that logically completes the text.

Anahtar Kavram

Logical Inferences
Soru 2536Soru

To create a specific shade of green paint, a painter mixes yellow paint and blue paint in a ratio of 3:53:5 by volume. To create a specific shade of teal paint, the painter mixes yellow paint and blue paint in a ratio of 1:31:3 by volume. If the painter mixes equal volumes of the green paint and the teal paint to create a new mixture, what is the ratio of yellow paint to blue paint in the new mixture?

Cevabı ve açıklamayı göster

Cevap: 5:11

Cevap

The ratio of yellow paint to blue paint in the new mixture is 5:11.
The correct answer is the option stating a ratio of 5:11. To find the ratio of yellow paint to blue paint in the final mixture, we first express the composition of each initial paint as fractions of the whole. For the green paint, yellow is 38\frac{3}{8} and blue is 58\frac{5}{8} of the volume. For the teal paint, yellow is 14\frac{1}{4} (or 28\frac{2}{8}) and blue is 34\frac{3}{4} (or 68\frac{6}{8}) of the volume. When equal volumes of the two paints are combined, the total fraction of yellow paint in the mixture is the average of the two individual yellow fractions, 12(38+28)=516\frac{1}{2} \left(\frac{3}{8} + \frac{2}{8}\right) = \frac{5}{16}. Similarly, the total fraction of blue paint is 12(58+68)=1116\frac{1}{2} \left(\frac{5}{8} + \frac{6}{8}\right) = \frac{11}{16}. Thus, the ratio of yellow paint to blue paint in the final mixture is 5:115:11.

Adım Adım Çözüm

1
Determine the fraction of yellow paint and blue paint in each of the two initial paint mixtures.
For the green paint, the ratio of yellow to blue is 3:53:5, meaning yellow paint is 33+5=38\frac{3}{3+5} = \frac{3}{8} of the volume, and blue paint is 58\frac{5}{8} of the volume. For the teal paint, the ratio of yellow to blue is 1:31:3, meaning yellow paint is 11+3=14\frac{1}{1+3} = \frac{1}{4} of the volume, and blue paint is 34\frac{3}{4} of the volume.
Converting part-to-part ratios into part-to-whole fractions is necessary to determine the absolute quantities of each component in a mixture of equal volumes.
2
Calculate the total fraction of yellow paint and blue paint in the combined mixture.
Since equal volumes VV of each paint are mixed, the total volume of the new mixture is 2V2V. The total volume of yellow paint is 38V+14V=38V+28V=58V\frac{3}{8}V + \frac{1}{4}V = \frac{3}{8}V + \frac{2}{8}V = \frac{5}{8}V. The total volume of blue paint is 58V+34V=58V+68V=118V\frac{5}{8}V + \frac{3}{4}V = \frac{5}{8}V + \frac{6}{8}V = \frac{11}{8}V.
Adding the parts of each ingredient from both paint types gives the total volume of each ingredient in the new mixture.
3
Find the ratio of yellow paint to blue paint in the final mixture by comparing their volumes.
The ratio of yellow paint to blue paint in the combined mixture is 58V:118V\frac{5}{8}V : \frac{11}{8}V, which simplifies to 5:115:11.
Simplifying the ratio of the volumes of yellow and blue paint gives the final part-to-part ratio for the new mixture.

Anahtar Kavram

Combining mixtures of different part-to-part ratios by converting them to part-to-whole fractions relative to a common total volume.
Tahmini Süre:1m 30s
Soru 2537Soru

The graph of the quadratic function ff in the xyxy-plane is defined by f(x)=x26x+5f(x) = x^2 - 6x + 5. If the graph of ff is translated 33 units to the left and 22 units down, which of the following equations defines the resulting function gg?

Cevabı ve açıklamayı göster

Cevap: g(x)=x26g(x) = x^2 - 6

Cevap

The equation that defines the function gg is g(x)=x26g(x) = x^2 - 6.
To find the function g(x)g(x), we apply the transformations to f(x)=x26x+5f(x) = x^2 - 6x + 5. A translation of 33 units to the left replaces xx with x+3x + 3, which gives f(x+3)=(x+3)26(x+3)+5=x2+6x+96x18+5=x24f(x + 3) = (x + 3)^2 - 6(x + 3) + 5 = x^2 + 6x + 9 - 6x - 18 + 5 = x^2 - 4. Next, translating the graph 22 units down corresponds to subtracting 22 from the function, resulting in g(x)=(x24)2=x26g(x) = (x^2 - 4) - 2 = x^2 - 6.

Adım Adım Çözüm

1
Rewrite the function f(x)f(x) in vertex form by completing the square.
f(x)=(x3)24f(x) = (x - 3)^2 - 4
Converting to vertex form a(xh)2+ka(x - h)^2 + k makes it straightforward to apply horizontal and vertical shifts based on the vertex (h,k)(h, k).
2
Apply the horizontal translation of 33 units to the left by replacing xx with x+3x + 3 in the function.
f(x+3)=((x+3)3)24=x24f(x + 3) = ((x + 3) - 3)^2 - 4 = x^2 - 4
A horizontal shift of cc units to the left is represented by replacing xx with x+cx + c.
3
Apply the vertical translation of 22 units down by subtracting 22 from the expression obtained in the previous step.
g(x)=(x24)2=x26g(x) = (x^2 - 4) - 2 = x^2 - 6
A vertical shift of dd units downward is represented by subtracting dd from the function's output.

Anahtar Kavram

Translations of quadratic functions in the coordinate plane.
Tahmini Süre:1m 30s
Soru 2538Soru

In right triangle ABCABC, the measure of angle CC is 9090^\circ, AC=15AC = 15, and BC=20BC = 20. Altitude CDCD is drawn to the hypotenuse ABAB. From point DD, perpendicular line segments DEDE and DFDF are drawn to sides ACAC and BCBC, respectively, where EE lies on ACAC and FF lies on BCBC. What is the ratio of the area of triangle CEFCEF to the area of triangle ABCABC?

Cevabı ve açıklamayı göster

Cevap: 144625\frac{144}{625}

Cevap

The ratio of the area of triangle CEFCEF to the area of triangle ABCABC is 144625\frac{144}{625}.
The correct answer is the fraction representing the ratio of the area of the smaller triangle to the larger triangle. This ratio can be computed by calculating the lengths of the legs of the right triangle CEFCEF using similarity relationships, yielding CE=9.6CE = 9.6 and CF=7.2CF = 7.2, which gives an area of 34.5634.56. Dividing this by the area of triangle ABCABC (150150) yields the fraction 144625\frac{144}{625}. Alternatively, the ratio is equal to the square of the ratio of the altitude to the hypotenuse, (CDAB)2=(1225)2=144625(\frac{CD}{AB})^2 = (\frac{12}{25})^2 = \frac{144}{625}.

Adım Adım Çözüm

1
Use the Pythagorean theorem to calculate the hypotenuse ABAB of the right triangle ABCABC.
AB=AC2+BC2=152+202=225+400=625=25AB = \sqrt{AC^2 + BC^2} = \sqrt{15^2 + 20^2} = \sqrt{225 + 400} = \sqrt{625} = 25
Knowing the hypotenuse allows us to calculate the altitude and set up similarity ratios.
2
Calculate the area of triangle ABCABC.
Area(ABC)=12×AC×BC=12×15×20=150\text{Area}(ABC) = \frac{1}{2} \times AC \times BC = \frac{1}{2} \times 15 \times 20 = 150
This establishes the base area to compare with the area of the smaller triangle.
3
Calculate the length of altitude CDCD by relating the area using base ABAB.
150=12×AB×CD150=12×25×CDCD=12150 = \frac{1}{2} \times AB \times CD \Rightarrow 150 = \frac{1}{2} \times 25 \times CD \Rightarrow CD = 12
The altitude is a key dimension that relates the nested geometry to the main triangle.
4
Identify the properties of the quadrilateral DECFDECF and the triangle CEFCEF.
DECFDECF is a rectangle with diagonals CD=EF=12CD = EF = 12, and CEF\triangle CEF is a right triangle with legs CECE and CFCF.
Since three angles are 9090^\circ (at CC, EE, and FF), the figure is a rectangle, meaning its diagonals are congruent.
5
Apply similarity properties to find the lengths of CECE and CFCF.
CE=9.6CE = 9.6 and CF=7.2CF = 7.2.
Using similar right triangles, CE=ACAE=155.4=9.6CE = AC - AE = 15 - 5.4 = 9.6 and CF=BCBF=2012.8=7.2CF = BC - BF = 20 - 12.8 = 7.2.
6
Calculate the area of right triangle CEFCEF and find the ratio.
Area(CEF)=12×9.6×7.2=34.56\text{Area}(CEF) = \frac{1}{2} \times 9.6 \times 7.2 = 34.56. The ratio is 34.56150=144625\frac{34.56}{150} = \frac{144}{625}. Alternatively, the ratio is (CDAB)2=(1225)2=144625\left(\frac{CD}{AB}\right)^2 = \left(\frac{12}{25}\right)^2 = \frac{144}{625}.
Comparing the two areas gives the final required ratio.

Anahtar Kavram

Area ratios and side lengths in similar right triangles using perpendicular projections.

Alternatif Yöntem

Using trigonometric ratios, we can express the lengths in terms of θ=A\theta = \angle A. Since CD=ABsinθcosθCD = AB \sin\theta \cos\theta, we have CE=CDsinθCE = CD \sin\theta and CF=CDcosθCF = CD \cos\theta. The area of triangle CEFCEF is 12CECF=12CD2sinθcosθ=CD2Area(ABC)AB2\frac{1}{2} CE \cdot CF = \frac{1}{2} CD^2 \sin\theta \cos\theta = CD^2 \frac{\text{Area}(ABC)}{AB^2}, which gives the area ratio as (CDAB)2\left(\frac{CD}{AB}\right)^2. Since AB=25AB = 25 and CD=12CD = 12, the ratio is (1225)2=144625\left(\frac{12}{25}\right)^2 = \frac{144}{625}.
Tahmini Süre:3m 0s
Soru 2539Soru

While researching the hunting behavior of archerfish, a student takes the following notes:
* Archerfish are freshwater fish known for hunting land-based insects by spitting streams of water.
* In a 2014 study, physicist Stefan Schuster and his team analyzed how archerfish control these water jets.
* The researchers discovered that the fish dynamically adjust the velocity of the water stream during release.
* This adjustment causes the water to gather into a single, high-impact droplet immediately before striking the target.
* The team concluded that archerfish actively calculate and modify the force of their spit based on the distance of their prey.

The student wants to summarize the study and its findings. Which choice most effectively uses information from the given notes to accomplish this goal?

Cevabı ve açıklamayı göster

Cevap: A 2014 study by Stefan Schuster and his team revealed that archerfish actively adjust the velocity of their water jets based on target distance to maximize the impact force on prey.

Cevap

The choice stating that a 2014 study by Stefan Schuster and his team revealed that archerfish actively adjust the velocity of their water jets based on target distance to maximize the impact force on prey.
The correct option effectively summarizes the 2014 study by Stefan Schuster and his team, noting both the methodology (analyzing water jet velocity) and the primary finding (that archerfish dynamically adjust the velocity based on distance to maximize impact force).

Adım Adım Çözüm

1
Identify the student's goal from the prompt.
The student wants to summarize the study and its findings.
This defines the criteria for the correct answer choice.
2
Evaluate the notes to determine the key elements of the study and its findings.
The key elements are a 2014 study by Stefan Schuster and his team on archerfish hunting, finding that they dynamically adjust velocity based on target distance to maximize force.
A correct summary must capture both the context of the study and the core conclusion rather than focusing on secondary details.
3
Examine the choices to find the one that incorporates these core elements without introducing errors or overgeneralizing.
The choice highlighting the active adjustment of water jet velocity based on distance to maximize prey impact force represents the most accurate and complete summary.
It satisfies the rhetorical goal of summarizing the study's findings directly, while other choices misrepresent details, focus on irrelevant points, or generalize too broadly.

Anahtar Kavram

Rhetorical Synthesis: Summarization and Generalization
Soru 2540Soru

In educational psychology, early models of learning assumed that instructional designs should minimize mental effort to facilitate immediate recall. However, contemporary research suggests that this approach may lead to rapid forgetting. Instead, introducing moderate cognitive challenges—known as 'desirable difficulties'—forces students to process information more deeply, thereby ensuring that the resulting knowledge is more _______

Which choice completes the text with the most logical and precise word or phrase?

Cevabı ve açıklamayı göster

Cevap: durable

Cevap

durable
The correct option is 'durable' because it means long-lasting or enduring. In the context of the passage, 'desirable difficulties' prevent 'rapid forgetting' by forcing students to process information more deeply, resulting in knowledge that is more stable and persistent over time.

Adım Adım Çözüm

1
Analyze the context of the sentence containing the blank.
The sentence explains that introducing moderate cognitive challenges forces students to process information more deeply, which prevents 'rapid forgetting' and ensures a positive learning outcome for the resulting knowledge.
Understanding the context helps identify the contrast between quick but easily forgotten information and deeply processed, long-lasting knowledge.
2
Evaluate the choices to find the word that best describes knowledge that is long-lasting and resistant to forgetting.
The word 'durable' precisely matches this meaning, whereas the other options describe qualities that are either opposite to the context or irrelevant to the longevity of knowledge.
This step identifies the correct high-utility vocabulary word that is semantically and grammatically precise in context.

Anahtar Kavram

Selecting the most precise and contextually appropriate vocabulary word to complete a text.
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