Tüm alıştırma soruları

13931 soru

Soru 7241Soru

If yy varies directly as xx, and y=20y = 20 when x=4x = 4, what is the value of yy when x=10x = 10?

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Cevap: 50

Cevap

The value of yy when x=10x = 10 is 50.
Direct variation means y=kxy = kx. Substituting y=20y = 20 and x=4x = 4 yields k=5k = 5. Substituting k=5k = 5 and x=10x = 10 gives y=50y = 50.

Adım Adım Çözüm

1
Set up the equation for direct variation
y=kxy = kx, where kk is the constant of variation.
Direct variation implies that yy is directly proportional to xx.
2
Substitute the given initial values (y=20y = 20, x=4x = 4) to find kk
20=k(4)    k=204=520 = k(4) \implies k = \frac{20}{4} = 5.
Determining the constant of variation allows us to write the specific relationship equation.
3
Calculate yy when x=10x = 10 using the constant k=5k = 5
y=5×10=50y = 5 \times 10 = 50.
Substituting x=10x = 10 into y=5xy = 5x yields the required value.

Anahtar Kavram

Direct Variation (y=kxy = kx)
Tahmini Süre:45s
Soru 7242Soru

What is the set of real values of xx that satisfies the quadratic inequality 2x25x302x^2 - 5x - 3 \le 0?

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Cevap: 12x3-\frac{1}{2} \le x \le 3

Cevap

12x3-\frac{1}{2} \le x \le 3
Factoring 2x25x32x^2 - 5x - 3 yields (2x+1)(x3)0(2x + 1)(x - 3) \le 0. Setting the factors to zero gives roots x=1/2x = -1/2 and x=3x = 3. Because the coefficient of x2x^2 is positive, the quadratic curve opens upwards and is less than or equal to zero in the closed interval between the roots, resulting in 12x3-\frac{1}{2} \le x \le 3.

Adım Adım Çözüm

1
Factor the quadratic expression 2x25x32x^2 - 5x - 3
(2x+1)(x3)0(2x + 1)(x - 3) \le 0
Finding the factors helps identify the critical points (roots) of the inequality.
2
Determine the critical points by setting each factor equal to zero
x=12x = -\frac{1}{2} and x=3x = 3
The critical points divide the real number line into test intervals.
3
Determine the region where (2x+1)(x3)0(2x + 1)(x - 3) \le 0
12x3-\frac{1}{2} \le x \le 3
Since the quadratic coefficient is positive (2>02 > 0), the parabola opens upwards, so the function values are less than or equal to zero between the two roots.

Anahtar Kavram

Solving Quadratic Inequalities by Factorisation
Soru 7243Soru

If y=ln(sec3x+tan3x)y = \ln(\sec 3x + \tan 3x), what is dydx\frac{dy}{dx}?

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Cevap: 3sec3x3\sec 3x

Cevap

3sec3x3\sec 3x
Using the chain rule for y=lnuy = \ln u where u=sec3x+tan3xu = \sec 3x + \tan 3x, we find u=3sec3xtan3x+3sec23x=3sec3x(tan3x+sec3x)u' = 3\sec 3x\tan 3x + 3\sec^2 3x = 3\sec 3x(\tan 3x + \sec 3x). Dividing uu' by uu cancels out (sec3x+tan3x)(\sec 3x + \tan 3x), leaving 3sec3x3\sec 3x.

Adım Adım Çözüm

1
Apply the chain rule for logarithmic functions ddx[ln(u)]=1ududx\frac{d}{dx}[\ln(u)] = \frac{1}{u}\frac{du}{dx}.
Set u=sec3x+tan3xu = \sec 3x + \tan 3x, so dydx=1sec3x+tan3xddx(sec3x+tan3x)\frac{dy}{dx} = \frac{1}{\sec 3x + \tan 3x} \cdot \frac{d}{dx}(\sec 3x + \tan 3x).
The function is a composite function of the form y=ln(u(x))y = \ln(u(x)).
2
Differentiate the inner function u=sec3x+tan3xu = \sec 3x + \tan 3x using the chain rule.
\frac{du}{dx} = 3\sec 3x \tan 3x + 3\sec^2 3x.
The derivative of sec(ax)\sec(ax) is asec(ax)tan(ax)a\sec(ax)\tan(ax) and the derivative of tan(ax)\tan(ax) is asec2(ax)a\sec^2(ax).
3
Factor out common terms in the numerator and simplify the expression.
\frac{dy}{dx} = \frac{3\sec 3x(\tan 3x + \sec 3x)}{\sec 3x + \tan 3x} = 3\sec 3x.
The term (tan3x+sec3x)(\tan 3x + \sec 3x) in the numerator cancels with the denominator (sec3x+tan3x)(\sec 3x + \tan 3x).

Anahtar Kavram

Differentiation of Logarithmic and Trigonometric Functions via the Chain Rule
Tahmini Süre:1m 30s
Soru 7244Soru

If y=e3xsin(2x)y = e^{3x} \sin(2x), what is dydx\frac{dy}{dx}?

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Cevap: e3x(3sin2x+2cos2x)e^{3x}(3\sin 2x + 2\cos 2x)

Cevap

e3x(3sin2x+2cos2x)e^{3x}(3\sin 2x + 2\cos 2x)
Using the product rule dydx=udvdx+vdudx\frac{dy}{dx} = u\frac{dv}{dx} + v\frac{du}{dx} on y=e3xsin(2x)y = e^{3x}\sin(2x) gives e3x2cos(2x)+sin(2x)3e3xe^{3x} \cdot 2\cos(2x) + \sin(2x) \cdot 3e^{3x}. Factoring out e3xe^{3x} results in e3x(3sin2x+2cos2x)e^{3x}(3\sin 2x + 2\cos 2x).

Adım Adım Çözüm

1
Identify the function components for the product rule
Let u=e3xu = e^{3x} and v=sin(2x)v = \sin(2x).
The function yy is a product of two differentiable functions u(x)u(x) and v(x)v(x).
2
Differentiate each component using the chain rule
dudx=3e3x\frac{du}{dx} = 3e^{3x} and dvdx=2cos(2x)\frac{dv}{dx} = 2\cos(2x).
Applying the chain rule gives ddx(e3x)=3e3x\frac{d}{dx}(e^{3x}) = 3e^{3x} and ddx(sin2x)=2cos2x\frac{d}{dx}(\sin 2x) = 2\cos 2x.
3
Apply the product rule formula dydx=udvdx+vdudx\frac{dy}{dx} = u \frac{dv}{dx} + v \frac{du}{dx}
dydx=e3x(2cos2x)+sin(2x)(3e3x)=e3x(3sin2x+2cos2x)\frac{dy}{dx} = e^{3x}(2\cos 2x) + \sin(2x)(3e^{3x}) = e^{3x}(3\sin 2x + 2\cos 2x).
Combining the products and factoring out the common exponential factor e3xe^{3x} yields the final derivative.

Anahtar Kavram

Differentiation of Transcendental Functions using Product Rule and Chain Rule
Tahmini Süre:1m 30s
Soru 7245Soru

If y=4x+1x2y = \frac{4x + 1}{x - 2}, calculate the numerical value of dydx\frac{dy}{dx} at x=3x = 3.

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Cevap: -9

Cevap

The numerical value of dydx\frac{dy}{dx} at x=3x = 3 is 9-9.
Using the quotient rule dydx=vdudxudvdxv2\frac{dy}{dx} = \frac{v\frac{du}{dx} - u\frac{dv}{dx}}{v^2} for y=4x+1x2y = \frac{4x + 1}{x - 2} gives dydx=(x2)(4)(4x+1)(1)(x2)2=9(x2)2\frac{dy}{dx} = \frac{(x - 2)(4) - (4x + 1)(1)}{(x - 2)^2} = \frac{-9}{(x - 2)^2}. Substituting x=3x = 3 produces 9(32)2=9\frac{-9}{(3 - 2)^2} = -9.

Adım Adım Çözüm

1
Identify u(x)u(x) and v(x)v(x) for the quotient rule formula.
u=4x+1u = 4x + 1 and v=x2v = x - 2.
The given equation y=4x+1x2y = \frac{4x + 1}{x - 2} is a quotient of two functions of xx.
2
Calculate the individual derivatives dudx\frac{du}{dx} and dvdx\frac{dv}{dx}.
dudx=4\frac{du}{dx} = 4 and dvdx=1\frac{dv}{dx} = 1.
These derivatives are required components of the quotient rule.
3
Substitute the expressions into the quotient rule formula dydx=vuuvv2\frac{dy}{dx} = \frac{v u' - u v'}{v^2} and simplify.
dydx=(x2)(4)(4x+1)(1)(x2)2=4x84x1(x2)2=9(x2)2\frac{dy}{dx} = \frac{(x - 2)(4) - (4x + 1)(1)}{(x - 2)^2} = \frac{4x - 8 - 4x - 1}{(x - 2)^2} = \frac{-9}{(x - 2)^2}.
Simplifying the numerator yields the general derivative function.
4
Evaluate the derivative at x=3x = 3.
dydxx=3=9(32)2=91=9\frac{dy}{dx}\Big|_{x=3} = \frac{-9}{(3 - 2)^2} = \frac{-9}{1} = -9.
Substituting x=3x = 3 gives the requested numerical value.

Anahtar Kavram

Quotient Rule of Differentiation
Soru 7246Soru

Evaluate the limit limx3x25x+6x3\lim_{x \to 3} \frac{x^2 - 5x + 6}{x - 3}. What is the numerical value of this limit?

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Cevap: 1

Cevap

The numerical value of the limit is 1.
Substituting x = 3 into the original expression produces the indeterminate form 0/0. Factoring the numerator gives (x - 3)(x - 2). Canceling the common factor (x - 3) yields x - 2. Substituting x = 3 into x - 2 gives 3 - 2 = 1.

Adım Adım Çözüm

1
Check the expression using direct substitution at x = 3.
The substitution yields \frac{3^2 - 5(3) + 6}{3 - 3} = \frac{0}{0}, an indeterminate form.
Direct substitution results in 0/0, indicating that algebraic factorization is needed.
2
Factorize the quadratic polynomial in the numerator.
x^2 - 5x + 6 = (x - 3)(x - 2)
Finding factors of +6 that sum to -5 allows cancellation of the denominator term.
3
Cancel the factor (x - 3) and evaluate the remaining linear expression at x = 3.
\lim_{x \to 3} (x - 2) = 3 - 2 = 1
The factor causing zero in the denominator is removed, leaving a continuous function.

Anahtar Kavram

Evaluating indeterminate limits (0/0) by algebraic factorization
Soru 7247Soru

Match each statistical data representation term on the left with its corresponding definition or mathematical property on the right.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

Class Boundary
Sector Angle
Frequency Density
Ogive

Eşleşmeler

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Cevap

Class Boundary matches with the value separating adjacent non-overlapping class intervals; Sector Angle matches with the central angle in a pie chart calculated as FrequencyTotal Frequency×360\frac{\text{Frequency}}{\text{Total Frequency}} \times 360^\circ; Frequency Density matches with the quotient of class frequency and class width; Ogive matches with a line graph produced by plotting cumulative frequencies against upper class boundaries.
Each data representation term directly corresponds to its core definition: class boundary closes gaps between discrete class intervals, sector angle measures central circle proportion in a pie chart, frequency density scales histogram height when class widths differ, and an ogive graphs cumulative frequency against upper boundaries.

Adım Adım Çözüm

1
Define Class Boundary
Class boundary is the continuous point midway between adjacent class limits.
Class boundaries remove gaps in discrete grouped frequency distributions.
2
Define Sector Angle formula for a pie chart
Sector Angle =FrequencyTotal Frequency×360= \frac{\text{Frequency}}{\text{Total Frequency}} \times 360^\circ.
The complete circle represents total frequency, so individual sectors scale proportionally with 360360^\circ.
3
Define Frequency Density for histograms
Frequency Density =FrequencyClass Width= \frac{\text{Frequency}}{\text{Class Width}}.
Histogram area equals frequency; when widths differ, height must represent frequency per unit width.
4
Define Ogive
An Ogive is a cumulative frequency curve plotted against upper boundaries.
Each point on an ogive shows the cumulative frequency up to that class's upper boundary.

Anahtar Kavram

Data Representation Terms and Formulas
Tahmini Süre:1m 30s
Soru 7248Soru

Find the smallest positive integer kk for which the inequality (k2)x2+8x+k+4>0(k - 2)x^2 + 8x + k + 4 > 0 holds for all real values of xx.

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Cevap: 5

Cevap

5
For the quadratic expression (k2)x2+8x+k+4(k - 2)x^2 + 8x + k + 4 to be positive for all real values of xx, two conditions must be satisfied simultaneously: the leading coefficient must be positive (k2>0    k>2k - 2 > 0 \implies k > 2) and the discriminant must be strictly negative (Δ<0\Delta < 0). Calculating the discriminant gives Δ=824(k2)(k+4)=968k4k2\Delta = 8^2 - 4(k - 2)(k + 4) = 96 - 8k - 4k^2. Setting 968k4k2<096 - 8k - 4k^2 < 0 and dividing by 4-4 (reversing the inequality) yields k2+2k24>0k^2 + 2k - 24 > 0, which factors as (k+6)(k4)>0(k + 6)(k - 4) > 0. This gives k<6k < -6 or k>4k > 4. Intersecting with k>2k > 2 results in k>4k > 4. The smallest integer greater than 4 is 5.

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1
Determine the conditions for positivity for all real numbers
k2>0k - 2 > 0 and Δ<0\Delta < 0
A quadratic Ax2+Bx+CAx^2 + Bx + C remains above the x-axis for all real xx if and only if its parabola opens upwards (A>0A > 0) and has no real roots (Δ<0\Delta < 0).
2
Set up and solve the discriminant inequality
k2+2k24>0    (k+6)(k4)>0k^2 + 2k - 24 > 0 \implies (k + 6)(k - 4) > 0
Expanding 824(k2)(k+4)<08^2 - 4(k - 2)(k + 4) < 0 gives 644(k2+2k8)<064 - 4(k^2 + 2k - 8) < 0, which simplifies to k2+2k24>0k^2 + 2k - 24 > 0 after dividing by 4-4 and reversing the inequality sign.
3
Intersect solution sets and find the smallest integer
k=5k = 5
The intersection of k>2k > 2 and (k<6 or k>4)(k < -6 \text{ or } k > 4) gives k>4k > 4. The smallest integer strictly greater than 4 is 5.

Anahtar Kavram

Condition for Positive Definite Quadratic Inequalities
Soru 7249Soru

A rhombus has diagonals of lengths 12 cm12\text{ cm} and 16 cm16\text{ cm}. What is the perimeter of the rhombus in cm\text{cm}?

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Cevap: 40

Cevap

The perimeter of the rhombus is 40 cm40\text{ cm}.
The diagonals of a rhombus bisect each other at right angles, dividing the rhombus into four congruent right-angled triangles. Each triangle has legs measuring 6 cm6\text{ cm} and 8 cm8\text{ cm}. Applying the Pythagorean theorem, the hypotenuse (which is the side length of the rhombus) is 62+82=100=10 cm\sqrt{6^2 + 8^2} = \sqrt{100} = 10\text{ cm}. Since all four sides of a rhombus are equal, the perimeter is 4×10=40 cm4 \times 10 = 40\text{ cm}.

Adım Adım Çözüm

1
Calculate the lengths of the semi-diagonals
The semi-diagonals are 6 cm6\text{ cm} and 8 cm8\text{ cm}.
The diagonals of a rhombus bisect each other perpendicularly.
2
Determine the side length of the rhombus using the Pythagorean theorem
Side length s=62+82=100=10 cms = \sqrt{6^2 + 8^2} = \sqrt{100} = 10\text{ cm}.
Each side of the rhombus forms the hypotenuse of a right-angled triangle formed by the semi-diagonals.
3
Calculate the total perimeter
Perimeter P=4×10=40 cmP = 4 \times 10 = 40\text{ cm}.
All four sides of a rhombus are equal in length.

Anahtar Kavram

Perimeter of a rhombus derived from diagonal lengths using right-triangle properties
Tahmini Süre:1m 0s
Soru 7250Soru
A piecewise function f(x)f(x) is defined by
f(x)={sin(3x)+tan(5x)2x,x0a25,x=0f(x) = \begin{cases} \frac{\sin(3x) + \tan(5x)}{2x}, & x \neq 0 \\ a^2 - 5, & x = 0 \end{cases}
If f(x)f(x) is continuous at x=0x = 0, where a>0a > 0, determine the numerical value of aa.
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Cevap: 3

Cevap

The numerical value of aa is 3.
For the function to be continuous at x=0x = 0, the limit as x0x \to 0 must equal the function value f(0)f(0). Splitting the trigonometric limit gives 32+52=4\frac{3}{2} + \frac{5}{2} = 4. Setting a25=4a^2 - 5 = 4 yields a2=9a^2 = 9. Because a>0a > 0, taking the positive square root gives a=3a = 3.

Adım Adım Çözüm

1
Evaluate the limit of the trigonometric expression as xx approaches 0.
\lim_{x \to 0} \frac{\sin(3x) + \tan(5x)}{2x} = 4
Using standard trigonometric limit principles: \lim_{x \to 0} \frac{\sin(kx)}{x} = k and \lim_{x \to 0} \frac{\tan(kx)}{x} = k.
2
Equate the limit value to f(0)f(0) to ensure continuity at x=0x = 0.
a^2 - 5 = 4
By definition, a function is continuous at x = c if and only if \lim_{x \to c} f(x) = f(c).
3
Solve the resulting quadratic equation for the positive constant aa.
a = 3
Adding 5 to both sides gives a^2 = 9; taking the principal square root gives a = 3 since a > 0.

Anahtar Kavram

Limits and Continuity of Functions
Soru 7251Soru

A binary operation Δ\Delta defined on the set of integers modulo 1111 is given by aΔb(2a23ab+b2)(mod11)a \Delta b \equiv (2a^2 - 3ab + b^2) \pmod{11}. Find the smallest non-negative integer xx that satisfies the equation 4Δx5(mod11)4 \Delta x \equiv 5 \pmod{11}.

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Cevap: 3

Cevap

The smallest non-negative integer xx that satisfies 4Δx5(mod11)4 \Delta x \equiv 5 \pmod{11} is 3.
Evaluating 4Δx4 \Delta x gives 3212x+x2x2x+10(mod11)32 - 12x + x^2 \equiv x^2 - x + 10 \pmod{11}. Setting this congruent to 5(mod11)5 \pmod{11} yields x2x+50(mod11)x^2 - x + 5 \equiv 0 \pmod{11}, which converts to x2x60(mod11)x^2 - x - 6 \equiv 0 \pmod{11}. Factoring gives (x3)(x+2)0(mod11)(x - 3)(x + 2) \equiv 0 \pmod{11}, which yields solutions x3(mod11)x \equiv 3 \pmod{11} and x9(mod11)x \equiv 9 \pmod{11}. The smallest non-negative integer among these solutions is 33.

Adım Adım Çözüm

1
Substitute the given value a=4a = 4 into the operation definition.
4Δx=2(4)23(4)x+x2=3212x+x24 \Delta x = 2(4)^2 - 3(4)x + x^2 = 32 - 12x + x^2
This establishes the explicit algebraic polynomial in terms of xx.
2
Reduce coefficients modulo 1111.
3210(mod11)32 \equiv 10 \pmod{11} and 12xx(mod11)-12x \equiv -x \pmod{11}, giving x2x+10(mod11)x^2 - x + 10 \pmod{11}.
Simplifying coefficients reduces computational complexity during equation solving.
3
Form the modular quadratic equation and set it to zero.
x2x+105(mod11)    x2x+50(mod11)    x2x60(mod11)x^2 - x + 10 \equiv 5 \pmod{11} \implies x^2 - x + 5 \equiv 0 \pmod{11} \implies x^2 - x - 6 \equiv 0 \pmod{11}.
Expressing 56(mod11)5 \equiv -6 \pmod{11} allows standard integer factorisation.
4
Factor the quadratic polynomial and solve for xx.
(x3)(x+2)0(mod11)    x3 or x29(mod11)(x - 3)(x + 2) \equiv 0 \pmod{11} \implies x \equiv 3 \text{ or } x \equiv -2 \equiv 9 \pmod{11}.
Since 1111 is prime, a product congruent to 0(mod11)0 \pmod{11} implies at least one factor is congruent to 0(mod11)0 \pmod{11}.
5
Select the smallest non-negative integer from the valid solution set {3,9}\{3, 9\}.
x=3x = 3
33 is non-negative and strictly smaller than 99.

Anahtar Kavram

Modular Arithmetic Binary Operations and Quadratic Congruences
Tahmini Süre:3m 0s
Soru 7252Soru

If the polynomial P(x)=x4+ax37x2+bx+12P(x) = x^4 + ax^3 - 7x^2 + bx + 12 is completely divisible by x22x3x^2 - 2x - 3, what is the value of aba - b?

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Cevap: 10-10

Cevap

The value of aba - b is 10-10.
Factoring x22x3x^2 - 2x - 3 gives (x3)(x+1)(x - 3)(x + 1). By the Factor Theorem, P(3)=0P(3) = 0 and P(1)=0P(-1) = 0. Substituting these into P(x)P(x) produces the linear system 9a+b=109a + b = -10 and a+b=6a + b = 6. Solving this system yields a=2a = -2 and b=8b = 8. Subtracting gives ab=28=10a - b = -2 - 8 = -10.

Adım Adım Çözüm

1
Factor the quadratic divisor to find the roots.
x22x3=(x3)(x+1)x^2 - 2x - 3 = (x - 3)(x + 1), so the roots are x=3x = 3 and x=1x = -1.
By the Factor Theorem, if a polynomial is divisible by a quadratic expression, P(x)P(x) must evaluate to zero at each root of the divisor.
2
Set up equations by evaluating P(3)=0P(3) = 0 and P(1)=0P(-1) = 0.
For x=3x = 3: 34+a(3)37(3)2+b(3)+12=0    81+27a63+3b+12=0    9a+b=103^4 + a(3)^3 - 7(3)^2 + b(3) + 12 = 0 \implies 81 + 27a - 63 + 3b + 12 = 0 \implies 9a + b = -10.
For x=1x = -1: (1)4+a(1)37(1)2+b(1)+12=0    1a7b+12=0    a+b=6(-1)^4 + a(-1)^3 - 7(-1)^2 + b(-1) + 12 = 0 \implies 1 - a - 7 - b + 12 = 0 \implies a + b = 6.
Evaluating the polynomial at each root yields a system of two linear equations in variables aa and bb.
3
Solve the simultaneous equations for aa and bb.
Subtracting (a+b=6)(a + b = 6) from (9a+b=10)(9a + b = -10) gives 8a=16    a=28a = -16 \implies a = -2.
Substituting a=2a = -2 into a+b=6a + b = 6 gives 2+b=6    b=8-2 + b = 6 \implies b = 8.
Elimination isolates aa, allowing both aa and bb to be uniquely determined.
4
Calculate aba - b.
ab=28=10a - b = -2 - 8 = -10.
This computes the required expression value.

Anahtar Kavram

Factor Theorem for quadratic divisors
Tahmini Süre:2m 0s
Soru 7253Soru

Let the universal set U={xZ:10x99}\mathcal{U} = \{x \in \mathbb{Z} : 10 \le x \le 99\}. Consider two subsets PP and QQ of U\mathcal{U}, where P={10a+bU:a>b}P = \{10a + b \in \mathcal{U} : a > b\} and Q={10a+bU:ab is odd}Q = \{10a + b \in \mathcal{U} : a \cdot b \text{ is odd}\}, with aa and bb representing the tens and units digits of xx respectively. What is the cardinality of the set PQP \setminus Q?

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Cevap: 35; 35 elements

Cevap

35
To evaluate n(PQ)n(P \setminus Q), we calculate n(P)n(PQ)n(P) - n(P \cap Q). Set PP consists of all two-digit numbers where the tens digit exceeds the units digit, giving 1+2++9=451 + 2 + \dots + 9 = 45 numbers. Set QQ consists of numbers with two odd digits. The intersection PQP \cap Q contains pairs of distinct odd digits (a,b)(a,b) where a>ba > b, which corresponds to (52)=10\binom{5}{2} = 10 pairs. Thus, n(PQ)=4510=35n(P \setminus Q) = 45 - 10 = 35.

Adım Adım Çözüm

1
Calculate the cardinality of set PP, denoted as n(P)n(P).
n(P)=45n(P) = 45
For a two-digit integer 10a+b10a + b, a{1,2,,9}a \in \{1, 2, \dots, 9\} and b{0,1,,9}b \in \{0, 1, \dots, 9\}. The condition a>ba > b yields 00 valid values of bb for a=1a=1 (1 choice: 10), 2 choices for a=2a=2 (20, 21), up to 9 choices for a=9a=9 (90 through 98). The total is a=19a=9×102=45\sum_{a=1}^9 a = \frac{9 \times 10}{2} = 45.
2
Calculate the cardinality of the intersection PQP \cap Q, denoted as n(PQ)n(P \cap Q).
n(PQ)=10n(P \cap Q) = 10
Set QQ contains numbers where the product aba \cdot b is odd, which requires both aa and bb to be odd digits chosen from {1,3,5,7,9}\{1, 3, 5, 7, 9\}. For PQP \cap Q, we need a>ba > b with distinct odd digits. The number of such pairs (a,b)(a, b) is given by choosing 2 distinct odd digits out of 5: (52)=10\binom{5}{2} = 10.
3
Calculate the cardinality of the set difference PQP \setminus Q.
n(PQ)=35n(P \setminus Q) = 35
Using the identity n(PQ)=n(P)n(PQ)n(P \setminus Q) = n(P) - n(P \cap Q), we get 4510=3545 - 10 = 35.

Anahtar Kavram

Cardinality of set difference and set-builder operations
Tahmini Süre:2m 30s
Soru 7254Soru

If y=esin2xln(tanx)y = e^{\sin 2x} \ln(\tan x), what is the value of dydx\frac{dy}{dx} at x=π4x = \frac{\pi}{4}?

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Cevap: 2e2e

Cevap

The derivative evaluated at x=π4x = \frac{\pi}{4} is 2e2e.
Applying the product rule dydx=uv+uv\frac{dy}{dx} = u'v + uv' to y=esin2xln(tanx)y = e^{\sin 2x} \ln(\tan x) gives u=2cos(2x)esin2xu' = 2\cos(2x)e^{\sin 2x} and v=2csc(2x)v' = 2\csc(2x). At x=π4x = \frac{\pi}{4}, cos(2x)=cos(π/2)=0\cos(2x) = \cos(\pi/2) = 0, which vanishes the first term. The second term evaluates to esin(π/2)2csc(π/2)=e12(1)=2ee^{\sin(\pi/2)} \cdot 2\csc(\pi/2) = e^1 \cdot 2(1) = 2e.

Adım Adım Çözüm

1
Identify the product rule structure for y=uvy = u \cdot v, where u=esin2xu = e^{\sin 2x} and v=ln(tanx)v = \ln(\tan x).
The product rule states dydx=uv+uv\frac{dy}{dx} = u'v + uv'.
The given function is a product of an exponential function and a logarithmic function.
2
Differentiate u=esin2xu = e^{\sin 2x} using the chain rule.
dudx=ddx(sin2x)esin2x=2cos(2x)esin2x\frac{du}{dx} = \frac{d}{dx}(\sin 2x) \cdot e^{\sin 2x} = 2\cos(2x) e^{\sin 2x}.
The inner function is sin2x\sin 2x, whose derivative is 2cos2x2\cos 2x.
3
Differentiate v=ln(tanx)v = \ln(\tan x) using the chain rule.
dvdx=1tanxsec2x=cosxsinx1cos2x=1sinxcosx=2csc(2x)\frac{dv}{dx} = \frac{1}{\tan x} \cdot \sec^2 x = \frac{\cos x}{\sin x} \cdot \frac{1}{\cos^2 x} = \frac{1}{\sin x \cos x} = 2\csc(2x).
Simplifying sec2xtanx\frac{\sec^2 x}{\tan x} gives 2sin2x=2csc(2x)\frac{2}{\sin 2x} = 2\csc(2x).
4
Combine terms into the product rule expression.
dydx=[2cos(2x)esin2xln(tanx)]+[esin2x2csc(2x)]\frac{dy}{dx} = [2\cos(2x) e^{\sin 2x} \ln(\tan x)] + [e^{\sin 2x} \cdot 2\csc(2x)].
Substitute u,u,v,vu, u', v, v' into dydx=uv+uv\frac{dy}{dx} = u'v + uv'.
5
Evaluate the derivative at x=π4x = \frac{\pi}{4}.
At x=π4x = \frac{\pi}{4}, 2x=π22x = \frac{\pi}{2}. Thus, cos(π/2)=0\cos(\pi/2) = 0, tan(π/4)=1    ln(1)=0\tan(\pi/4) = 1 \implies \ln(1) = 0, sin(π/2)=1\sin(\pi/2) = 1, and csc(π/2)=1\csc(\pi/2) = 1. The first term becomes 00, and the second term becomes e12(1)=2ee^{1} \cdot 2(1) = 2e. Thus, dydx=2e\frac{dy}{dx} = 2e.
Substitute special angle values into the expression to compute the numerical result.

Anahtar Kavram

Product Rule and Chain Rule for Transcendental Functions
Soru 7255Soru

Simplify the expression 33133+1\frac{\sqrt{3}}{\sqrt{3} - 1} - \frac{\sqrt{3}}{\sqrt{3} + 1}.

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Cevap: 3\sqrt{3}

Cevap

3\sqrt{3}
Combining the fractions using the common denominator (31)(3+1)=2(\sqrt{3}-1)(\sqrt{3}+1) = 2 gives a numerator of 3(3+1)3(31)=3+33+3=23\sqrt{3}(\sqrt{3}+1) - \sqrt{3}(\sqrt{3}-1) = 3 + \sqrt{3} - 3 + \sqrt{3} = 2\sqrt{3}. Dividing 232\sqrt{3} by 22 yields the simplified answer 3\sqrt{3}.

Adım Adım Çözüm

1
Find a common denominator for the two fractions
The common denominator is (31)(3+1)=(3)2(1)2=31=2(\sqrt{3} - 1)(\sqrt{3} + 1) = (\sqrt{3})^2 - (1)^2 = 3 - 1 = 2
The denominators are conjugate surds, so their product simplifies to a rational number using the difference of two squares.
2
Express the numerator over the common denominator
Numerator =3(3+1)3(31)= \sqrt{3}(\sqrt{3} + 1) - \sqrt{3}(\sqrt{3} - 1)
Multiply each numerator by the missing factor of the common denominator.
3
Expand and simplify the numerator
Numerator =(3+3)(33)=3+33+3=23= (3 + \sqrt{3}) - (3 - \sqrt{3}) = 3 + \sqrt{3} - 3 + \sqrt{3} = 2\sqrt{3}
Distribute 3\sqrt{3} and handle the subtraction sign carefully.
4
Divide the simplified numerator by the common denominator
232=3\frac{2\sqrt{3}}{2} = \sqrt{3}
Cancel the common factor of 2.

Anahtar Kavram

Rationalisation of denominators and algebraic manipulation of surd fractions
Tahmini Süre:1m 15s
Soru 7256Soru

Line ABAB is parallel to line CDCD. A transversal line EFEF intersects line ABAB at point PP and line CDCD at point QQ. If APQ=(4x10)\angle APQ = (4x - 10)^\circ and PQD=(2x+30)\angle PQD = (2x + 30)^\circ are alternate interior angles, what is the measure of BPQ\angle BPQ?

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Cevap: 110110^\circ

Cevap

110110^\circ
Since alternate interior angles are equal, 4x10=2x+304x - 10 = 2x + 30, yielding x=20x = 20. Thus, APQ=70\angle APQ = 70^\circ. Because APQ\angle APQ and BPQ\angle BPQ are adjacent angles on straight line ABAB, their sum is 180180^\circ, giving BPQ=110\angle BPQ = 110^\circ.

Adım Adım Çözüm

1
Set up the equation for alternate interior angles.
4x10=2x+304x - 10 = 2x + 30
Alternate interior angles formed by a transversal cutting parallel lines are equal.
2
Solve the linear equation for xx.
2x=40    x=202x = 40 \implies x = 20
Subtract 2x2x and add 1010 to both sides.
3
Calculate the measure of APQ\angle APQ.
\angle APQ = 4(20) - 10 = 70^\circ$
Substitute x=20x = 20 into the expression (4x10)(4x - 10)^\circ.
4
Determine BPQ\angle BPQ using the straight line angle property.
\angle BPQ = 180^\circ - 70^\circ = 110^\circ$
Angles APQ\angle APQ and BPQ\angle BPQ form a linear pair on straight line ABAB, summing to 180180^\circ.

Anahtar Kavram

Alternate interior angles of parallel lines and angles on a straight line
Soru 7257Soru

When evaluating the derivative of the cubic function f(x)=2x35xf(x) = 2x^3 - 5x from first principles, which of the following expressions represents the fully simplified difference quotient f(x+h)f(x)h\frac{f(x+h) - f(x)}{h} prior to taking the limit as h0h \to 0?

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Cevap: 6x2+6xh+2h256x^2 + 6xh + 2h^2 - 5

Cevap

The simplified difference quotient before evaluating the limit is 6x2+6xh+2h256x^2 + 6xh + 2h^2 - 5.
Expanding f(x+h)=2(x+h)35(x+h)f(x+h) = 2(x+h)^3 - 5(x+h) using the binomial expansion yields 2x3+6x2h+6xh2+2h35x5h2x^3 + 6x^2h + 6xh^2 + 2h^3 - 5x - 5h. Subtracting f(x)=2x35xf(x) = 2x^3 - 5x leaves 6x2h+6xh2+2h35h6x^2h + 6xh^2 + 2h^3 - 5h. Dividing each term by hh gives the correct simplified difference quotient 6x2+6xh+2h256x^2 + 6xh + 2h^2 - 5.

Adım Adım Çözüm

1
Express f(x+h)f(x+h) for the function f(x)=2x35xf(x) = 2x^3 - 5x
f(x+h)=2(x+h)35(x+h)=2(x3+3x2h+3xh2+h3)5x5h=2x3+6x2h+6xh2+2h35x5hf(x+h) = 2(x+h)^3 - 5(x+h) = 2(x^3 + 3x^2h + 3xh^2 + h^3) - 5x - 5h = 2x^3 + 6x^2h + 6xh^2 + 2h^3 - 5x - 5h
Substitute (x+h)(x+h) into f(x)f(x) and expand the binomial terms completely.
2
Subtract f(x)f(x) from f(x+h)f(x+h) to find the numerator f(x+h)f(x)f(x+h) - f(x)
f(x+h)f(x)=(2x3+6x2h+6xh2+2h35x5h)(2x35x)=6x2h+6xh2+2h35hf(x+h) - f(x) = (2x^3 + 6x^2h + 6xh^2 + 2h^3 - 5x - 5h) - (2x^3 - 5x) = 6x^2h + 6xh^2 + 2h^3 - 5h
Cancel out the common terms 2x32x^3 and 5x-5x.
3
Divide the numerator by hh to form the difference quotient
\frac{6x^2h + 6xh^2 + 2h^3 - 5h}{h} = 6x^2 + 6xh + 2h^2 - 5
Factor out hh from each term in the numerator and divide by hh.

Anahtar Kavram

Differentiation from First Principles
Soru 7258Soru

A rectangular garden measuring 12 m12\text{ m} by 8 m8\text{ m} has a paved path of uniform width x mx\text{ m} constructed inside it along its perimeter. If the area of the remaining inner garden is 60 m260\text{ m}^2, what is the width xx of the path?

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Cevap: 1 m1\text{ m}

Cevap

The width of the path is 1 m1\text{ m}.
The total outer garden area is 12×8=96 m212 \times 8 = 96\text{ m}^2. Subtracting the path width xx from both ends gives inner dimensions (122x)(12 - 2x) and (82x)(8 - 2x). Equating the inner area (122x)(82x)=60(12 - 2x)(8 - 2x) = 60 yields x210x+9=0x^2 - 10x + 9 = 0. The realistic physical solution is x=1 mx = 1\text{ m}.

Adım Adım Çözüm

1
Express the inner dimensions in terms of path width xx
Length = (122x) m(12 - 2x)\text{ m}, Width = (82x) m(8 - 2x)\text{ m}
The path reduces each side dimension by xx at both ends.
2
Set up the area equation for the inner rectangular garden
(122x)(82x)=60(12 - 2x)(8 - 2x) = 60
The area of a rectangle is length multiplied by width.
3
Expand and simplify the quadratic equation
9640x+4x2=60    4x240x+36=0    x210x+9=096 - 40x + 4x^2 = 60 \implies 4x^2 - 40x + 36 = 0 \implies x^2 - 10x + 9 = 0
Divide the whole equation by 4 to simplify quadratic terms.
4
Solve for xx by factoring
(x1)(x9)=0    x=1(x - 1)(x - 9) = 0 \implies x = 1 or x=9x = 9
Since the width xx cannot exceed half of the smaller side (x<4 mx < 4\text{ m}), x=9x = 9 is extraneous.

Anahtar Kavram

Perimeter and Area of Rectangles with Uniform Borders
Tahmini Süre:1m 30s
Soru 7259Soru

What is the exact simplified value of sin60+cos45\sin 60^\circ + \cos 45^\circ?

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Cevap: 3+22\frac{\sqrt{3} + \sqrt{2}}{2}

Cevap

3+22\frac{\sqrt{3} + \sqrt{2}}{2}
Substituting the exact values sin60=32\sin 60^\circ = \frac{\sqrt{3}}{2} and cos45=22\cos 45^\circ = \frac{\sqrt{2}}{2} gives 32+22=3+22\frac{\sqrt{3}}{2} + \frac{\sqrt{2}}{2} = \frac{\sqrt{3} + \sqrt{2}}{2}.

Adım Adım Çözüm

1
Identify the exact trigonometric values for the special angles.
sin60=32\sin 60^\circ = \frac{\sqrt{3}}{2} and cos45=22\cos 45^\circ = \frac{\sqrt{2}}{2}
Standard special angle values in trigonometry.
2
Substitute the values into the given expression.
32+22\frac{\sqrt{3}}{2} + \frac{\sqrt{2}}{2}
Direct substitution of known ratio values.
3
Combine the fractions over the common denominator of 22.
3+22\frac{\sqrt{3} + \sqrt{2}}{2}
Adding numerators over a shared common denominator.

Anahtar Kavram

Special Angles and Exact Trigonometric Values
Soru 7260Soru

A normal line is drawn to the curve y=x25x3y = \frac{x^2 - 5}{x - 3} at the point where x=2x = 2. What is the xx-intercept of this normal line?

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Cevap: -1

Cevap

The xx-intercept of the normal line is 1-1.
Substituting x=2x = 2 into the curve yields the point (2,1)(2, 1). Differentiation via the quotient rule gives dydx=x26x+5(x3)2\frac{dy}{dx} = \frac{x^2 - 6x + 5}{(x - 3)^2}. At x=2x = 2, the tangent slope is 3-3, making the normal slope 13\frac{1}{3}. The line equation y1=13(x2)y - 1 = \frac{1}{3}(x - 2) simplifies to x3y+1=0x - 3y + 1 = 0. Setting y=0y = 0 gives x=1x = -1.

Adım Adım Çözüm

1
Calculate the y-coordinate of the point of tangency
y=1y = 1
Substitute x=2x = 2 into the curve equation y=x25x3y = \frac{x^2 - 5}{x - 3} to get the point (2,1)(2, 1).
2
Differentiate the function using the quotient rule
dydx=x26x+5(x3)2\frac{dy}{dx} = \frac{x^2 - 6x + 5}{(x - 3)^2}
Applying ddx(uv)=uvuvv2\frac{d}{dx}\left(\frac{u}{v}\right) = \frac{u'v - uv'}{v^2} to u=x25u = x^2 - 5 and v=x3v = x - 3.
3
Find the tangent gradient at x=2x = 2
mt=3m_t = -3
Evaluate dydx\frac{dy}{dx} at x=2x = 2 to obtain mt=226(2)+5(23)2=3m_t = \frac{2^2 - 6(2) + 5}{(2-3)^2} = -3.
4
Calculate the gradient of the normal line
mn=13m_n = \frac{1}{3}
The normal line is perpendicular to the tangent line, so mn=1mt=13m_n = -\frac{1}{m_t} = \frac{1}{3}.
5
Derive the line equation for the normal
x3y+1=0x - 3y + 1 = 0
Use point-slope form yy1=mn(xx1)y - y_1 = m_n(x - x_1) with (2,1)(2, 1) and mn=13m_n = \frac{1}{3}.
6
Find the x-intercept
x=1x = -1
Set y=0y = 0 in the normal equation x3(0)+1=0x - 3(0) + 1 = 0, giving x=1x = -1.

Anahtar Kavram

Equation of normal line to a rational curve and finding its axis intercepts
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