Tüm alıştırma soruları

2789 soru

Soru 2581Soru

In triangle PQRPQR, point SS lies on side PQPQ and point TT lies on side PRPR such that segment STST is parallel to segment QRQR. The length of segment PSPS is xx, the length of segment SQSQ is 66, the length of segment STST is x+2x + 2, and the length of segment QRQR is 2x+72x + 7. What is the length of segment QRQR?

Cevabı ve açıklamayı göster

Cevap: 15

Cevap

The length of segment QRQR is 1515.
Since segment STST is parallel to segment QRQR, triangle PSTPST is similar to triangle PQRPQR. The ratio of their corresponding sides is equal, so PSPQ=STQR\frac{PS}{PQ} = \frac{ST}{QR}. Substituting the values gives xx+6=x+22x+7\frac{x}{x + 6} = \frac{x + 2}{2x + 7}. Cross-multiplying and simplifying yields x2x12=0x^2 - x - 12 = 0. Factoring gives (x4)(x+3)=0(x-4)(x+3)=0, so x=4x=4 because side lengths must be positive. Substituting x=4x=4 into 2x+72x+7 yields 1515.

Adım Adım Çözüm

1
Determine the similarity between the triangles
Triangle PSTPST is similar to triangle PQRPQR
Since segment STST is parallel to segment QRQR, the corresponding angles are equal, establishing similarity by Angle-Angle (AA) criterion.
2
Express the total length of side PQPQ
PQ=x+6PQ = x + 6
The length of side PQPQ is the sum of the collinear segments PSPS and SQSQ.
3
Set up the similarity ratio equation
xx+6=x+22x+7\frac{x}{x + 6} = \frac{x + 2}{2x + 7}
Corresponding side lengths of similar triangles are in proportion: PSPQ=STQR\frac{PS}{PQ} = \frac{ST}{QR}.
4
Solve the quadratic equation for xx
x=4x = 4
Cross-multiplying gives x(2x+7)=(x+2)(x+6)    2x2+7x=x2+8x+12    x2x12=0    (x4)(x+3)=0x(2x + 7) = (x + 2)(x + 6) \implies 2x^2 + 7x = x^2 + 8x + 12 \implies x^2 - x - 12 = 0 \implies (x - 4)(x + 3) = 0. Since length must be positive, x=4x = 4.
5
Calculate the length of segment QRQR
QR=15QR = 15
Substitute x=4x = 4 into the expression for QRQR, which is 2x+72x + 7, resulting in 2(4)+7=152(4) + 7 = 15.

Anahtar Kavram

Using triangle similarity and algebraic equations to find unknown segment lengths.
Soru 2582Soru

Materials scientists studying spider silk have long marvelled at its combination of high tensile strength and extensibility, which allows webs to absorb the impact of flying prey without breaking. ______ researchers have found that dragline silk, the main support thread of a web, can stretch up to forty percent of its original length and support weights comparable to high-grade steel before fracturing.

Which choice completes the text with the most logical transition?

Cevabı ve açıklamayı göster

Cevap: Specifically,

Cevap

Specifically,
The correct option is 'Specifically' because the first sentence makes a general claim about the impressive tensile strength and extensibility of spider silk, and the second sentence provides specific, concrete details illustrating these two properties (stretching up to forty percent and supporting steel-like weights).

Adım Adım Çözüm

1
Analyze the relationship between the first and second sentences.
The first sentence introduces general properties of spider silk (tensile strength and extensibility). The second sentence provides specific, concrete data supporting these properties (stretching forty percent and supporting weights comparable to steel).
Identifying the relationship helps determine the correct logical category of transition needed.
2
Identify the transition category.
Since the second sentence elaborates on or provides a specific example of the first, an elaboration or exemplification transition is required.
Matching the semantic relationship to the appropriate transition type narrows down the choices.
3
Evaluate the choices against the required category.
'Specifically' fits the elaboration category, whereas 'Conversely' denotes contrast, 'Consequently' denotes cause-effect, and 'Subsequently' denotes sequence.
Verifying which option fits the category ensures the correct logical transition is selected.

Anahtar Kavram

Transitions: Elaboration and Exemplification
Soru 2583Soru

For an acute angle θ\theta, the expression sin4(θ)cos4(θ)sin(θ)cos(θ)\frac{\sin^4(\theta) - \cos^4(\theta)}{\sin(\theta) - \cos(\theta)} is equal to 75\frac{7}{5}. What is the value of 25sin(θ)cos(θ)25\sin(\theta)\cos(\theta)?

Cevabı ve açıklamayı göster

Cevap: 12

Cevap

The correct answer is 12.
The expression sin4(θ)cos4(θ)sin(θ)cos(θ)\frac{\sin^4(\theta) - \cos^4(\theta)}{\sin(\theta) - \cos(\theta)} simplifies directly to sin(θ)+cos(θ)=75\sin(\theta) + \cos(\theta) = \frac{7}{5} by applying the difference of squares identity twice and substituting the Pythagorean identity sin2(θ)+cos2(θ)=1\sin^2(\theta) + \cos^2(\theta) = 1. Squaring both sides of this simplified equation gives sin2(θ)+2sin(θ)cos(θ)+cos2(θ)=4925\sin^2(\theta) + 2\sin(\theta)\cos(\theta) + \cos^2(\theta) = \frac{49}{25}. Replacing sin2(θ)+cos2(θ)\sin^2(\theta) + \cos^2(\theta) with 1 yields 1+2sin(θ)cos(θ)=49251 + 2\sin(\theta)\cos(\theta) = \frac{49}{25}, which simplifies to sin(θ)cos(θ)=1225\sin(\theta)\cos(\theta) = \frac{12}{25}. Multiplying this result by 25 gives the final integer value of 12.

Adım Adım Çözüm

1
Factor the numerator of the expression.
sin4(θ)cos4(θ)=(sin2(θ)cos2(θ))(sin2(θ)+cos2(θ))\sin^4(\theta) - \cos^4(\theta) = (\sin^2(\theta) - \cos^2(\theta))(\sin^2(\theta) + \cos^2(\theta))
The difference of squares identity can be applied to terms with fourth powers.
2
Apply the Pythagorean identity to simplify the factored numerator.
sin4(θ)cos4(θ)=sin2(θ)cos2(θ)\sin^4(\theta) - \cos^4(\theta) = \sin^2(\theta) - \cos^2(\theta)
The Pythagorean trigonometric identity states that sin2(θ)+cos2(θ)=1\sin^2(\theta) + \cos^2(\theta) = 1.
3
Factor the remaining term in the numerator.
sin2(θ)cos2(θ)=(sin(θ)cos(θ))(sin(θ)+cos(θ))\sin^2(\theta) - \cos^2(\theta) = (\sin(\theta) - \cos(\theta))(\sin(\theta) + \cos(\theta))
This is another application of the difference of squares identity.
4
Simplify the fraction by dividing the common factor in the numerator and denominator.
sin(θ)+cos(θ)=75\sin(\theta) + \cos(\theta) = \frac{7}{5}
The term sin(θ)cos(θ)\sin(\theta) - \cos(\theta) in the numerator and denominator cancels out since θ\theta is an acute angle and sin(θ)cos(θ)\sin(\theta) \neq \cos(\theta).
5
Square both sides of the simplified equation.
sin2(θ)+2sin(θ)cos(θ)+cos2(θ)=4925\sin^2(\theta) + 2\sin(\theta)\cos(\theta) + \cos^2(\theta) = \frac{49}{25}
Squaring both sides allows us to relate the sum sin(θ)+cos(θ)\sin(\theta) + \cos(\theta) to the product sin(θ)cos(θ)\sin(\theta)\cos(\theta).
6
Substitute the Pythagorean identity and solve for the product of sine and cosine.
sin(θ)cos(θ)=1225\sin(\theta)\cos(\theta) = \frac{12}{25}
Substituting sin2(θ)+cos2(θ)=1\sin^2(\theta) + \cos^2(\theta) = 1 yields 1+2sin(θ)cos(θ)=49251 + 2\sin(\theta)\cos(\theta) = \frac{49}{25}, which simplifies to 2sin(θ)cos(θ)=24252\sin(\theta)\cos(\theta) = \frac{24}{25}.
7
Multiply the product by 25 to find the target value.
12
The question asks for the value of 25sin(θ)cos(θ)25\sin(\theta)\cos(\theta).

Anahtar Kavram

Simplifying trigonometric expressions using algebraic factorization and Pythagorean identities.

Alternatif Yöntem

Since θ\theta is an acute angle in a right triangle, we can test standard Pythagorean triples. A right triangle with side lengths 3, 4, and 5 has an angle θ\theta where sin(θ)=35\sin(\theta) = \frac{3}{5} and cos(θ)=45\cos(\theta) = \frac{4}{5}. Checking these values in the simplified expression gives sin(θ)+cos(θ)=35+45=75\sin(\theta) + \cos(\theta) = \frac{3}{5} + \frac{4}{5} = \frac{7}{5}, which matches the given condition. We can then directly calculate 25sin(θ)cos(θ)=25(35)(45)=1225\sin(\theta)\cos(\theta) = 25 \left(\frac{3}{5}\right)\left(\frac{4}{5}\right) = 12.
Tahmini Süre:3m 0s
Soru 2584Soru

A circle has a central angle of 6060^\circ that subtends an arc of length 4π4\pi. What is the circumference of the circle?

Cevabı ve açıklamayı göster

Cevap: 24π24\pi

Cevap

The circumference of the circle is 24π24\pi.
The correct answer is 24π24\pi. A full circle is 360360^\circ. A central angle of 6060^\circ represents 60360=16\frac{60^\circ}{360^\circ} = \frac{1}{6} of the entire circle. Therefore, the length of the arc subtended by this angle is 16\frac{1}{6} of the total circumference. To find the circumference, we multiply the arc length by 66: 4π×6=24π4\pi \times 6 = 24\pi.

Adım Adım Çözüm

1
Find the fraction of the circle represented by the 6060^\circ central angle.
60360=16\frac{60^\circ}{360^\circ} = \frac{1}{6}
A full circle has a central angle of 360360^\circ, so the fraction of the circle is the ratio of the given central angle to 360360^\circ.
2
Set up the proportion relating the arc length to the total circumference (CC).
16=4πC\frac{1}{6} = \frac{4\pi}{C}
The ratio of the arc length to the total circumference equals the ratio of the central angle to the total degree measure of a circle.
3
Solve for the circumference (CC) by multiplying both sides by 66.
C=6×4π=24πC = 6 \times 4\pi = 24\pi
Multiplying the arc length of the sector by the reciprocal of the fraction yields the total circumference of the circle.

Anahtar Kavram

Finding the circumference of a circle given the central angle and the subtended arc length using proportional reasoning.
Soru 2585Soru

An agricultural department monitored the population of honeybee colonies in two adjacent conservation areas starting in 2018 (t=0t = 0). In Area 1, the number of colonies increases by a constant 230 colonies each year. In Area 2, the number of colonies increases by a constant 10% each year. At t=0t = 0, both areas had 2,000 colonies. If the model for Area 1 predicts LL colonies at t=3t = 3 and the model for Area 2 predicts EE colonies at t=3t = 3, what is the value of LEL - E?

Cevabı ve açıklamayı göster

Cevap: 28

Cevap

28
To find the value of LEL - E, the populations projected by each model at t=3t = 3 must be calculated.

For Area 1, the growth is linear with an initial population of 2,000 and a constant annual increase of 230. The model is L(t)=2000+230tL(t) = 2000 + 230t. At t=3t = 3, the population is L(3)=2000+230(3)=2690L(3) = 2000 + 230(3) = 2690.

For Area 2, the growth is exponential with an initial population of 2,000 and a constant annual increase of 10%. The model is E(t)=2000(1.10)tE(t) = 2000(1.10)^t. At t=3t = 3, the population is E(3)=2000(1.10)3=2000(1.331)=2662E(3) = 2000(1.10)^3 = 2000(1.331) = 2662.

Subtracting the exponential model output from the linear model output yields LE=26902662=28L - E = 2690 - 2662 = 28.

Adım Adım Çözüm

1
Model the population growth for Area 1.
L(t)=2000+230tL(t) = 2000 + 230t. For t=3t = 3, L(3)=2000+230(3)=2000+690=2690L(3) = 2000 + 230(3) = 2000 + 690 = 2690. Thus, L=2690L = 2690.
Since Area 1 increases by a constant number of colonies (230) each year, its growth is linear. The initial population is 2,000.
2
Model the population growth for Area 2.
E(t)=2000(1.10)tE(t) = 2000(1.10)^t. For t=3t = 3, E(3)=2000(1.10)3=2000(1.331)=2662E(3) = 2000(1.10)^3 = 2000(1.331) = 2662. Thus, E=2662E = 2662.
Since Area 2 increases by a constant percentage (10%) each year, its growth is exponential with a growth factor of 1+0.10=1.101 + 0.10 = 1.10.
3
Calculate the difference LEL - E.
LE=26902662=28L - E = 2690 - 2662 = 28.
We need to find the difference between the linear model's prediction and the exponential model's prediction at t=3t = 3.

Anahtar Kavram

Linear growth increases by a constant amount per unit of time, whereas exponential growth increases by a constant percentage (or multiplies by a constant factor) per unit of time.

Alternatif Yöntem

Instead of setting up equations, the population values can be calculated step-by-step for each year.
Year 1 (t=1t = 1):
Area 1: 2000+230=22302000 + 230 = 2230
Area 2: 2000×1.10=22002000 \times 1.10 = 2200

Year 2 (t=2t = 2):
Area 1: 2230+230=24602230 + 230 = 2460
Area 2: 2200×1.10=24202200 \times 1.10 = 2420

Year 3 (t=3t = 3):
Area 1: 2460+230=26902460 + 230 = 2690
Area 2: 2420×1.10=26622420 \times 1.10 = 2662

Subtracting the two values at Year 3 gives the final result: 26902662=282690 - 2662 = 28.
Tahmini Süre:1m 30s
Soru 2586Soru

A transportation planner wants to estimate the proportion of commuters in a city who regularly use public transit to travel to work. The city has 60,00060,000 commuters. The planner conducts a survey by randomly selecting 300300 commuters from a database of registered transit pass holders in the city and finds that 240240 of them regularly use public transit to travel to work. Which of the following is the most appropriate conclusion based on the design of the survey?

Cevabı ve açıklamayı göster

Cevap: No reliable conclusion can be drawn about all commuters in the city because the sample is not representative of all commuters.

Cevap

No reliable conclusion can be drawn about all commuters in the city because the sample is not representative of all commuters.
The correct option correctly states that no reliable conclusion can be drawn about all commuters in the city. Because the sample was drawn exclusively from registered transit pass holders, it is highly likely to contain a disproportionately high percentage of public transit users. Thus, the sample is biased and cannot be used to generalize to the entire commuter population.

Adım Adım Çözüm

1
Identify the target population and the sample source.
Target population: All 60,00060,000 commuters in the city. Sample source: Registered transit pass holders.
To evaluate the validity of a study, we must check if the sample selection source matches the target population.
2
Assess the representativeness of the sample.
The sample is biased because registered transit pass holders are much more likely to regularly use public transit than a typical commuter in the city.
A representative sample must give every member of the target population an equal chance of selection.
3
Determine the appropriate scope of generalization.
Since the sample is not representative of all commuters, the results cannot be generalized to the entire city population.
Generalization is only valid when the sample is representative of the target population.

Anahtar Kavram

Generalizing results from a sample to a population requires a representative, randomly selected sample from that entire population.
Tahmini Süre:1m 30s
Soru 2587Soru

Plants often defend against herbivores by emitting volatile organic compounds (VOCs) that recruit predatory insects. Producing VOCs requires significant nitrogen, a nutrient essential for plant growth. In a study of *Solanum lycopersicum* (tomato plants), researchers observed that plants grown in nitrogen-deficient soil reduced their VOC emissions by over 60% when attacked by caterpillars, compared to plants in nitrogen-rich soil. However, the nitrogen-deficient plants showed a corresponding increase in the production of glandular trichomes (hair-like structures on leaves), which physically impede herbivores and are composed primarily of carbon. Because carbon is abundant even in nutrient-poor soils, researchers concluded that under nitrogen limitations, *Solanum lycopersicum* shifts its defense strategy. Which choice most logically completes the text?

Cevabı ve açıklamayı göster

Cevap: away from chemical signals that recruit predatory insects and toward physical structures that hinder pests directly.

Cevap

The correct answer states that under nitrogen limitations, *Solanum lycopersicum* shifts its defense strategy away from chemical signals that recruit predatory insects and toward physical structures that hinder pests directly.
The passage establishes that VOC production (which recruits predatory insects) is nitrogen-dependent and decreases significantly under nitrogen deficiency. Conversely, the production of glandular trichomes (physical barriers) is carbon-based and increases because carbon is abundant. Therefore, the plant shifts its defense strategy away from the nitrogen-intensive chemical attraction of predators toward carbon-based physical barriers that directly obstruct herbivores.

Adım Adım Çözüm

1
Identify the two defense mechanisms described in the passage.
The plant utilizes volatile organic compounds (VOCs) to attract predators, and glandular trichomes to physically block herbivores.
Establishing the options for defense is necessary to track how the plant's behavior changes.
2
Analyze the resource constraints for each defense mechanism.
VOCs are nitrogen-dependent, and nitrogen is scarce in poor soils. Glandular trichomes are carbon-based, and carbon is abundant even in poor soils.
Understanding the resource availability explains why the plant cannot maintain both defenses equally.
3
Evaluate the observed shift in the plant's response under nutrient limitation.
When nitrogen is limited, the plant reduces its nitrogen-costly VOC emissions by over 60% but increases its carbon-based trichomes.
Synthesizing these observations leads to the logical conclusion that the plant shifts its strategy from the chemical recruitment method to the physical barrier method.

Anahtar Kavram

Logical Inferences under resource constraints
Soru 2588Soru

Iron is an essential micronutrient for human health, but excess levels can lead to tissue damage. In 2001, researchers discovered that the liver secretes a peptide hormone called hepcidin, which serves as the primary regulator of systemic iron balance. Hepcidin acts by binding to ferroportin, the only known cellular iron exporter found on the surface of macrophages and enterocytes. Upon binding, hepcidin induces the internalization and degradation of ferroportin. This action directly halts the release of iron into the blood plasma, effectively lowering circulating iron levels. Consequently, when hepcidin levels are abnormally low, ferroportin remains active, leading to excessive iron absorption and accumulation in vital organs.

According to the text, how does hepcidin affect circulating iron levels?

Cevabı ve açıklamayı göster

Cevap: It induces the internalization and degradation of ferroportin, which halts the release of iron into the blood plasma.

Cevap

Hepcidin lowers circulating iron levels by binding to ferroportin and causing it to be internalized and degraded, thereby preventing iron from being released into the blood plasma.
The correct option is directly supported by the passage, which explicitly describes how hepcidin binding to ferroportin induces its internalization and degradation, halting the release of iron into the blood plasma and lowering circulating levels.

Adım Adım Çözüm

1
Identify where the text explains the mechanism by which hepcidin lowers iron levels.
The text states: 'Upon binding, hepcidin induces the internalization and degradation of ferroportin. This action directly halts the release of iron into the blood plasma, effectively lowering circulating iron levels.'
This locates the specific explicit details addressing the question stem.
2
Match the text's description with the choices provided.
The statement describing the internalization and degradation of ferroportin matches the text exactly.
Explicit detail questions require finding the option that restates text details without introducing external assumptions.

Anahtar Kavram

Identifying Explicit Details
Tahmini Süre:1m 30s
Soru 2589Soru

In a right triangle, the two acute angles are θ\theta and ϕ\phi. If sin(θ)=725\sin(\theta) = \frac{7}{25} and cos(ϕ)=k50\cos(\phi) = \frac{k}{50}, what is the value of kk?

Cevabı ve açıklamayı göster

Cevap: 14

Cevap

14
In any right triangle, the two acute angles, θ\theta and ϕ\phi, must sum to 9090^\circ. The cofunction trigonometric identity states that sin(θ)=cos(90θ)=cos(ϕ)\sin(\theta) = \cos(90^\circ - \theta) = \cos(\phi). Therefore, we can equate the two given values: 725=k50\frac{7}{25} = \frac{k}{50}. Solving this equation for kk gives k=7×5025=14k = \frac{7 \times 50}{25} = 14.

Adım Adım Çözüm

1
Determine the relationship between the two acute angles in a right triangle.
θ+ϕ=90\theta + \phi = 90^\circ
Since the sum of the angles in any triangle is 180180^\circ and a right triangle has one 9090^\circ angle, the sum of the other two acute angles must be 9090^\circ.
2
Apply the cofunction trigonometric identity for complementary angles.
sin(θ)=cos(ϕ)\sin(\theta) = \cos(\phi)
The sine of an acute angle is always equal to the cosine of its complement.
3
Equate the given expressions and solve for kk.
725=k50    k=14\frac{7}{25} = \frac{k}{50} \implies k = 14
Substitute the given values into the identity and multiply both sides by 5050 to isolate kk.

Anahtar Kavram

Cofunction identities for complementary angles in a right triangle
Soru 2590Soru

For a cubic polynomial function pp, the graph of y=p(x)y = p(x) in the xyxy-plane has xx-intercepts at (1,0)(1, 0) and (4,0)(4, 0), and x+3x + 3 is a factor of p(x)p(x). If p(0)=24p(0) = -24, what is the value of p(2)p(2)?

Cevabı ve açıklamayı göster

Cevap: 20

Cevap

20
The correct answer is 20. By translating the factor x+3x + 3 and the intercepts (1,0)(1, 0) and (4,0)(4, 0) into roots, the polynomial can be modeled as p(x)=a(x+3)(x1)(x4)p(x) = a(x + 3)(x - 1)(x - 4). Solving for the leading coefficient using p(0)=24p(0) = -24 yields a=2a = -2. Substituting x=2x = 2 into the resulting equation p(x)=2(x+3)(x1)(x4)p(x) = -2(x + 3)(x - 1)(x - 4) gives p(2)=2(5)(1)(2)=20p(2) = -2(5)(1)(-2) = 20.

Adım Adım Çözüm

1
Identify the roots of the polynomial from the factors and intercepts.
The roots of p(x)p(x) are x=3x = -3, x=1x = 1, and x=4x = 4.
A factor of x+3x + 3 corresponds to a root of 3-3. The xx-intercepts at (1,0)(1, 0) and (4,0)(4, 0) correspond to roots at 11 and 44.
2
Write the general factored form of the cubic polynomial.
p(x)=a(x+3)(x1)(x4)p(x) = a(x + 3)(x - 1)(x - 4)
A cubic polynomial with known roots r1,r2,r3r_1, r_2, r_3 can be expressed as p(x)=a(xr1)(xr2)(xr3)p(x) = a(x-r_1)(x-r_2)(x-r_3).
3
Use the value p(0)=24p(0) = -24 to find the constant coefficient aa.
a=2a = -2
Substituting x=0x = 0 gives p(0)=a(0+3)(01)(04)=12ap(0) = a(0 + 3)(0 - 1)(0 - 4) = 12a. Since 12a=2412a = -24, we solve to find a=2a = -2.
4
Evaluate p(2)p(2) using the fully defined polynomial.
p(2)=20p(2) = 20
Substituting x=2x = 2 into p(x)=2(x+3)(x1)(x4)p(x) = -2(x + 3)(x - 1)(x - 4) yields p(2)=2(2+3)(21)(24)=2(5)(1)(2)=20p(2) = -2(2 + 3)(2 - 1)(2 - 4) = -2(5)(1)(-2) = 20.

Anahtar Kavram

Using polynomial roots, factors, and given coordinates to define and evaluate polynomial functions.
Soru 2591Soru

Museum conservators face unique challenges when protecting organic artifacts. In museum curation, the long-term preservation of historic oil paintings on delicate wood panels, which are highly sensitive to sudden fluctuations in relative humidity, ________ a combination of stable microclimates and precise environmental monitoring to prevent the wood from warping. Conservators must therefore rely on advanced climate control systems to maintain stable conditions.

Which choice completes the text so that it conforms to the conventions of Standard English?

Cevabı ve açıklamayı göster

Cevap: demands

Cevap

demands
The singular verb 'demands' correctly agrees with the singular subject of the sentence, 'preservation.' Intervening descriptive elements such as 'of historic oil paintings on delicate wood panels' do not affect the singular status of the subject.

Adım Adım Çözüm

1
Locate the subject of the clause containing the blank.
The subject is 'preservation,' which is a singular noun.
Finding the head noun of the subject phrase is necessary to determine if a singular or plural verb is required.
2
Identify and disregard any intervening phrases or clauses between the subject and the verb.
The prepositional phrase 'of historic oil paintings on delicate wood panels' and the relative clause 'which are highly sensitive to sudden fluctuations in relative humidity' both modify the subject but do not change its grammatical number.
Intervening phrases containing plural nouns often distract from the true singular subject.
3
Select the verb option that is singular and fits the grammatical structure of the sentence.
'demands' is the correct singular present-tense verb form. 'demand' and 'have demanded' are plural, and 'demanding' is a non-finite verb.
A singular subject must be paired with a singular verb to maintain subject-verb agreement.

Anahtar Kavram

Subject-Verb Agreement
Soru 2592Soru

Architects and master builders in medieval Europe developed key Gothic architectural innovations not just to achieve aesthetic grandeur, but to solve pressing structural engineering challenges. ______ they introduced the ribbed vault and the pointed arch to distribute the immense weight of stone ceilings more efficiently than the heavy, semi-circular Romanesque vaults could.

Which choice completes the passage with the most logical transition?

Cevabı ve açıklamayı göster

Cevap: Specifically

Cevap

Specifically
The correct transition is 'specifically' because the second sentence elaborates on the first by providing concrete examples of the Gothic architectural innovations (the ribbed vault and pointed arch) and explaining how they solved the structural challenges mentioned. This relationship of exemplification and elaboration is logically signaled by 'specifically'.

Adım Adım Çözüm

1
Analyze the relationship between the two sentences.
The first sentence introduces the general concept of Gothic architectural innovations designed to solve engineering challenges, while the second sentence names specific innovations (ribbed vaults and pointed arches) that illustrate this concept.
Identifying the logical connection between the ideas is necessary to choose the correct transition.
2
Determine the transition category needed.
Since the second sentence elaborates on and provides specific examples of the general innovations mentioned in the first, an elaboration or exemplification transition is required.
The correct transition must match the identified logical relationship.
3
Evaluate the choices against the required category.
'Specifically' is an elaboration transition that fits the context, whereas 'conversely' (contrast), 'consequently' (cause-and-effect), and 'subsequently' (chronology) do not.
Eliminating incorrect transition categories isolates the correct option.

Anahtar Kavram

Transitions: Elaboration and Exemplification
Soru 2593Soru

The function h(t)=16t2+v0t+h0h(t) = -16t^2 + v_0 t + h_0 models the height h(t)h(t), in feet, of a model rocket tt seconds after launch, where v0v_0 and h0h_0 are constants. The rocket reaches its maximum height of 100100 feet above the ground 22 seconds after it is launched. Which of the following equations defines h(t)h(t)?

Cevabı ve açıklamayı göster

Cevap: h(t)=16t2+64t+36h(t) = -16t^2 + 64t + 36

Cevap

h(t)=16t2+64t+36h(t) = -16t^2 + 64t + 36
The correct equation is h(t)=16t2+64t+36h(t) = -16t^2 + 64t + 36. Since the maximum height of 100100 feet is reached at t=2t = 2 seconds, the vertex of the parabola is (2,100)(2, 100). In vertex form, a quadratic function is written as h(t)=a(td)2+ch(t) = a(t - d)^2 + c, where (d,c)(d, c) is the vertex. Given that the leading coefficient aa is 16-16, substituting the vertex yields h(t)=16(t2)2+100h(t) = -16(t - 2)^2 + 100. Expanding this expression gives h(t)=16(t24t+4)+100=16t2+64t64+100=16t2+64t+36h(t) = -16(t^2 - 4t + 4) + 100 = -16t^2 + 64t - 64 + 100 = -16t^2 + 64t + 36.

Adım Adım Çözüm

1
Identify the vertex from the problem description.
The vertex of the parabola is (2,100)(2, 100), representing the time t=2t = 2 seconds when the maximum height of 100100 feet is reached.
The vertex (h,k)(h, k) of a quadratic function represents the maximum or minimum point of its graph.
2
Write the quadratic equation in vertex form.
h(t)=a(t2)2+100h(t) = a(t - 2)^2 + 100. Since the coefficient of t2t^2 in the standard form is 16-16, we set a=16a = -16, giving h(t)=16(t2)2+100h(t) = -16(t - 2)^2 + 100.
The vertex form of a quadratic function is y=a(xh)2+ky = a(x - h)^2 + k, and the leading coefficient aa is the same as in standard form.
3
Expand the vertex form equation into standard form.
h(t)=16(t24t+4)+100=16t2+64t64+100=16t2+64t+36h(t) = -16(t^2 - 4t + 4) + 100 = -16t^2 + 64t - 64 + 100 = -16t^2 + 64t + 36.
Expanding the squared term and distributing the leading coefficient converts the vertex form to standard form y=ax2+bx+cy = ax^2 + bx + c.

Anahtar Kavram

Quadratic Functions and Graphs

Alternatif Yöntem

The axis of symmetry for a quadratic function in standard form y=ax2+bx+cy = ax^2 + bx + c is given by x=b2ax = -\frac{b}{2a}. For this model, the maximum occurs at t=2t = 2, meaning the axis of symmetry is t=2t = 2. Since a=16a = -16, we have 2=b2(16)2 = -\frac{b}{2(-16)}, which simplifies to b=64b = 64. We can then test the remaining options where the linear coefficient is 6464. Substituting t=2t = 2 into the correct equation h(t)=16t2+64t+36h(t) = -16t^2 + 64t + 36 yields h(2)=16(4)+64(2)+36=64+128+36=100h(2) = -16(4) + 64(2) + 36 = -64 + 128 + 36 = 100, confirming it reaches the correct maximum height.
Tahmini Süre:1m 30s
Soru 2594Soru

In a circle with center OO, central angle AOBAOB has a measure of 5π6\frac{5\pi}{6} radians. If the radius of the circle is 1212, the length of arc ABAB is kπk\pi. What is the value of kk?

Cevabı ve açıklamayı göster

Cevap: 10

Cevap

The value of kk is 1010.
The arc length ss subtended by a central angle θ\theta (in radians) in a circle of radius rr is given by s=rθs = r\theta. Substituting the radius r=12r = 12 and the angle θ=5π6\theta = \frac{5\pi}{6} yields s=12×5π6=10πs = 12 \times \frac{5\pi}{6} = 10\pi. Since the arc length is expressed as kπk\pi, the value of kk is 1010.

Adım Adım Çözüm

1
Identify the formula for arc length in radians.
s=rθs = r\theta
The arc length ss is directly proportional to the radius rr and the central angle θ\theta in radians.
2
Substitute the given values into the formula.
s=12×5π6s = 12 \times \frac{5\pi}{6}
The radius of the circle is 1212 and the central angle is 5π6\frac{5\pi}{6} radians.
3
Calculate the arc length.
s=10πs = 10\pi
Simplifying 12×5612 \times \frac{5}{6} gives 2×5=102 \times 5 = 10, so the product is 10π10\pi.
4
Determine the value of kk.
k=10k = 10
We equate the calculated arc length 10π10\pi with the given expression kπk\pi.

Anahtar Kavram

Arc length of a circle using radian measure
Tahmini Süre:45s
Soru 2595Soru

In behavioral economics, the "endowment effect" describes the tendency of individuals to value an item they own more highly than an equivalent item they do not own. To investigate its underlying mechanism, researcher Emily Vance conducted an experiment where one group was given a mug (owners) and another was given money (buyers). Vance hypothesized that if the effect is driven primarily by loss aversion—the pain of losing an item exceeding the pleasure of gaining it—then owners would value the mug much higher than buyers. However, a third group, allowed only to choose between receiving the mug or the money, valued the mug just as highly as the owners did. Which choice most logically completes the text?

Cevabı ve açıklamayı göster

Cevap: This finding suggests that the higher valuation of an owned item is not primarily caused by the aversion to losing it.

Cevap

This finding suggests that the higher valuation of an owned item is not primarily caused by the aversion to losing it.
The choice proposing that the higher valuation of an owned item is not primarily caused by the aversion to losing it is correct. If loss aversion (the pain of losing an item) were the main reason owners valued the mug more than buyers, then the group that did not own the mug (the choosers) should not have valued it as highly as the owners did. However, because the choosers valued the mug just as highly as the owners, the difference in valuation cannot be explained by loss aversion.

Adım Adım Çözüm

1
Analyze the researcher's hypothesis.
Vance hypothesized that the difference in valuation between owners and buyers is driven by loss aversion (the pain of losing ownership).
To identify the baseline theory being tested.
2
Examine the results of the third group (choosers).
The choosers did not own the mug (hence had no ownership to lose) but valued the mug just as highly as the owners.
To determine if the lack of ownership changes the valuation.
3
Draw a logical inference based on the comparison of the groups.
Because the group without ownership valued the mug identically to the group with ownership, loss aversion cannot be the primary explanation for the high valuation.
To identify the conclusion that is directly supported by the experimental evidence.

Anahtar Kavram

Evaluating experimental evidence to draw a logical conclusion about a hypothesis.
Tahmini Süre:1m 30s
Soru 2596Soru

Many plant species possess sophisticated defense mechanisms that allow them to warn neighboring foliage of impending herbivore attacks. ______ when an acacia tree is browsed by an antelope, it releases volatile ethylene gas into the air, signaling nearby acacias to immediately ramp up their production of toxic tannins.

Which choice completes the text with the most logical transition?

Cevabı ve açıklamayı göster

Cevap: For example,

Cevap

For example,
The correct answer is the option containing 'For example,'. The first sentence states a general claim about plants warning neighboring foliage of attacks. The second sentence provides a specific instance of this phenomenon: an acacia tree releasing ethylene gas to warn neighboring acacias when browsed by an antelope. Therefore, the transition 'For example' logically connects the general statement to the specific illustration.

Adım Adım Çözüm

1
Analyze the relationship between the first and second sentences.
The first sentence makes a general claim: plants have defense mechanisms to warn neighbors of herbivore attacks. The second sentence describes a specific scenario: acacia trees releasing ethylene gas to signal other acacias when browsed by antelopes.
Understanding the logical connection between the ideas is necessary to choose the correct transition.
2
Identify the type of transition required.
Since the second sentence illustrates the general claim of the first sentence with a specific case, an exemplification transition is needed.
The logical flow goes from a general rule to a specific example.
3
Evaluate the choices to find the one that fits this relationship.
The transition 'For example' matches this exemplification relationship, while the other choices represent contrast ('Nevertheless'), addition ('Furthermore'), or sequence ('Subsequently').
Selecting the transition that matches the logical relationship ensures the text flows coherently.

Anahtar Kavram

Exemplification and Elaboration Transitions
Soru 2597Soru

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

Aşağıdaki boşlukları doldurun

While studying the personal journals of novelist Virginia Woolf, scholars noted that she frequently revised even the most mundane descriptions of her daily routine. This meticulous attention to detail suggests that Woolf's seemingly spontaneous prose style was actually the product of planning rather than simple intuition.
Cevabı ve açıklamayı göster

Cevap

deliberate (or a similar word indicating intentional, careful, or methodical planning)
The text contrasts Virginia Woolf's 'seemingly spontaneous' style with her actual practice of revising mundane descriptions and paying 'meticulous attention to detail.' This indicates that her planning was not accidental or intuitive, but rather intentional, conscious, and carefully executed. The word 'deliberate' (or synonyms like 'intentional' and 'methodical') precisely captures this meaning.

Adım Adım Çözüm

1
Analyze the context of the sentence to identify the contrast being set up.
The sentence contrasts the 'seemingly spontaneous prose style' of Virginia Woolf with the actual process behind it, marked by 'meticulous attention to detail' and 'frequently revised' descriptions.
Understanding the relationship between the ideas in the sentence helps determine the meaning of the missing word.
2
Identify the word that describes planning that is the opposite of 'spontaneous' and 'simple intuition' while aligning with 'meticulous attention to detail'.
The planning must be conscious, intentional, and carefully thought out, which is best described by the word 'deliberate'.
The correct vocabulary word must be logically and precisely supported by the clues in the text.

Anahtar Kavram

Identifying logical relationships and context clues to determine precise vocabulary in academic texts.
Tahmini Süre:1m 30s
Soru 2598Soru

In the xyxy-plane, the terminal ray of an angle θ\theta in standard position intersects the unit circle at a point PP. If the line passing through PP and the point (0,1)(0, 1) has a slope of 12-\frac{1}{2}, what is the value of sin(θ)\sin(\theta)?

Cevabı ve açıklamayı göster

Cevap: 35\frac{3}{5}

Cevap

three-fifths
The correct answer is three-fifths. Since the point PP lies on the unit circle, its coordinates are (cos(θ),sin(θ))(\cos(\theta), \sin(\theta)). Using the slope formula between PP and the point (0,1)(0, 1), we get the equation sin(θ)1cos(θ)=12\frac{\sin(\theta) - 1}{\cos(\theta)} = -\frac{1}{2}. Cross-multiplying and rearranging gives cos(θ)=2(1sin(θ))\cos(\theta) = 2(1 - \sin(\theta)). Substituting this into the Pythagorean identity cos2(θ)+sin2(θ)=1\cos^2(\theta) + \sin^2(\theta) = 1 yields the quadratic equation 5sin2(θ)8sin(θ)+3=05\sin^2(\theta) - 8\sin(\theta) + 3 = 0. Factoring this equation gives (5sin(θ)3)(sin(θ)1)=0(5\sin(\theta) - 3)(\sin(\theta) - 1) = 0, which gives the solutions sin(θ)=35\sin(\theta) = \frac{3}{5} or sin(θ)=1\sin(\theta) = 1. Since the line is defined by two distinct points, PP cannot be (0,1)(0, 1), which means sin(θ)1\sin(\theta) \neq 1. Thus, sin(θ)=35\sin(\theta) = \frac{3}{5}.

Adım Adım Çözüm

1
Represent the point PP on the unit circle using trigonometric functions and set up the slope equation with the point (0,1)(0,1).
The slope equation is sin(θ)1cos(θ)=12\frac{\sin(\theta) - 1}{\cos(\theta)} = -\frac{1}{2}.
Since PP lies on the unit circle, its coordinates are (cos(θ),sin(θ))(\cos(\theta), \sin(\theta)). The slope of a line through (x1,y1)(x_1, y_1) and (x2,y2)(x_2, y_2) is y2y1x2x1\frac{y_2 - y_1}{x_2 - x_1}.
2
Express cos(θ)\cos(\theta) in terms of sin(θ)\sin(\theta) by cross-multiplying and isolating cos(θ)\cos(\theta) in the equation.
cos(θ)=2(1sin(θ))\cos(\theta) = 2(1 - \sin(\theta)).
This substitution variable will allow us to rewrite the Pythagorean identity in terms of a single variable, sin(θ)\sin(\theta).
3
Substitute the expression for cos(θ)\cos(\theta) into the Pythagorean trigonometric identity cos2(θ)+sin2(θ)=1\cos^2(\theta) + \sin^2(\theta) = 1 and simplify.
4(1sin(θ))2+sin2(θ)=1    5sin2(θ)8sin(θ)+3=04(1 - \sin(\theta))^2 + \sin^2(\theta) = 1 \implies 5\sin^2(\theta) - 8\sin(\theta) + 3 = 0.
The Pythagorean identity is a fundamental relationship between the sine and cosine of any angle.
4
Factor the quadratic equation to find the possible values of sin(θ)\sin(\theta), and reject any extraneous solutions.
(5sin(θ)3)(sin(θ)1)=0(5\sin(\theta) - 3)(\sin(\theta) - 1) = 0, giving sin(θ)=35\sin(\theta) = \frac{3}{5} or sin(θ)=1\sin(\theta) = 1. The value sin(θ)=1\sin(\theta) = 1 is rejected because it makes the point PP identical to (0,1)(0, 1), meaning a line cannot be defined.
A line requires two distinct points to be defined with a specific slope.

Anahtar Kavram

Unit circle definitions and the Pythagorean trigonometric identity
Soru 2599Soru

For decades, historians and archaeologists debated the origins of the complex agricultural terraces in the Andes, with many early researchers asserting that these systems were imported by foreign cultures. However, recent sediment analyses and carbon-dating of the soil have _______ this hypothesis, demonstrating that indigenous communities developed these sophisticated farming techniques independently over centuries.

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

Cevabı ve açıklamayı göster

Cevap: refuted

Cevap

refuted
The correct answer is 'refuted'. The passage sets up a contrast between the historical assumption that Andean terraces were imported and the new evidence showing they were developed locally. The word 'However' signals that the new evidence disproves the early hypothesis, making the word meaning disproved the most logical and precise choice.

Adım Adım Çözüm

1
Analyze the context and transition words in the passage.
The passage begins with an old assertion (that Andean terraces were imported by foreign cultures) and introduces new findings using the contrast word 'However'. The new findings demonstrate that indigenous communities developed the techniques independently, which contradicts the old assertion.
Identifying the relationship between the old assertion and the new findings is necessary to determine if the blank requires a word meaning support or disproof.
2
Select the word that matches the identified contrast relationship.
Since the new findings contradict and disprove the old assertion, a word meaning 'disproved' is required. The word 'refuted' fits this definition precisely.
Matching the contextual need with the correct definition ensures a precise vocabulary choice.

Anahtar Kavram

Words in Context: High-Utility Vocabulary
Soru 2600Soru

A research group conducted a survey using a random sample of 250250 residents of a town with a total population of 18,00018,000 residents. Of the residents surveyed, 64%64\% reported that they recycle regularly. The survey has a margin of error of 3%3\%. Based on the survey results, what is the difference between the maximum and minimum estimated number of residents in the town who recycle regularly?

Cevabı ve açıklamayı göster

Cevap: 1080

Cevap

The correct answer is 1,080.
The sample proportion is 64%64\% with a margin of error of 3%3\%, which establishes an interval of 61%61\% to 67%67\% for the proportion of the population that recycles regularly. Multiplying these boundaries by the total population of 18,00018,000 yields a minimum estimate of 0.61×18,000=10,9800.61 \times 18,000 = 10,980 residents and a maximum estimate of 0.67×18,000=12,0600.67 \times 18,000 = 12,060 residents. The difference between the maximum and minimum estimated number of residents is 12,06010,980=1,08012,060 - 10,980 = 1,080. Alternatively, this difference can be found by multiplying the total width of the interval (2×0.03=0.062 \times 0.03 = 0.06) by the population size (0.06×18,000=1,0800.06 \times 18,000 = 1,080).

Adım Adım Çözüm

1
Determine the range of the proportion of residents who recycle regularly.
The proportion ranges from 61%61\% (0.610.61) to 67%67\% (0.670.67).
The margin of error of 3%3\% is subtracted from and added to the sample proportion of 64%64\%.
2
Calculate the minimum and maximum estimated number of residents who recycle regularly.
The minimum estimate is 10,98010,980 residents and the maximum estimate is 12,06012,060 residents.
Multiply the minimum and maximum proportions by the total population of 18,00018,000: 0.61×18,000=10,9800.61 \times 18,000 = 10,980 and 0.67×18,000=12,0600.67 \times 18,000 = 12,060.
3
Find the difference between the maximum and minimum estimated values.
12,06010,980=1,08012,060 - 10,980 = 1,080 (or alternatively, 2×0.03×18,000=1,0802 \times 0.03 \times 18,000 = 1,080).
Subtracting the minimum estimate from the maximum estimate yields the difference.

Anahtar Kavram

Using sample statistics and margin of error to estimate population parameters.
ÖncekiSayfa 130 / 140Sonraki
Tüm alıştırma soruları — SAT | Examkin