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541 soru

Soru 401Soru

In rhombus ABCDABCD, the perimeter is 100100 and the length of diagonal BDBD is 3030. Point PP lies on diagonal ACAC such that the ratio of the length of segment APAP to the length of segment PCPC is 3:73:7. What is the length of segment BPBP?

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Cevap: 17

Cevap

The length of segment BPBP is 17.
The correct answer is found by utilizing the properties of a rhombus. A rhombus has four congruent sides, meaning each side of a rhombus with perimeter 100100 has a length of 2525. The diagonals of a rhombus are perpendicular bisectors of one another. Letting OO be the intersection of the diagonals, we find BO=15BO = 15 since diagonal BD=30BD = 30. Using the Pythagorean theorem on right triangle AOBAOB, we determine that the other half-diagonal is AO=252152=20AO = \sqrt{25^2 - 15^2} = 20, which means the full diagonal AC=40AC = 40. Point PP divides ACAC in the ratio 3:73:7, meaning AP=12AP = 12 and PC=28PC = 28. The distance from PP to the intersection point OO is OP=AOAP=2012=8OP = AO - AP = 20 - 12 = 8. Finally, applying the Pythagorean theorem to right triangle BOPBOP with legs BO=15BO = 15 and OP=8OP = 8 yields BP=152+82=17BP = \sqrt{15^2 + 8^2} = 17.

Adım Adım Çözüm

1
Calculate the side length of rhombus ABCDABCD from its perimeter.
Each side length is 2525.
A rhombus has four equal sides, so the side length is the perimeter divided by four: 1004=25\frac{100}{4} = 25.
2
Find the length of half of diagonal BDBD.
BO=15BO = 15, where OO is the intersection of diagonals ACAC and BDBD.
The diagonals of a rhombus bisect each other.
3
Calculate the half-diagonal length AOAO and full diagonal length ACAC.
AO=20AO = 20 and AC=40AC = 40.
The diagonals of a rhombus are perpendicular, forming right triangle AOBAOB. By the Pythagorean theorem, AO=AB2BO2=252152=20AO = \sqrt{AB^2 - BO^2} = \sqrt{25^2 - 15^2} = 20. Since the diagonals bisect each other, the total length of diagonal ACAC is 2×20=402 \times 20 = 40.
4
Determine the length of segment APAP.
AP=12AP = 12.
Point PP lies on diagonal ACAC such that the ratio of segment APAP to PCPC is 3:73:7. Therefore, AP=33+7×AC=310×40=12AP = \frac{3}{3+7} \times AC = \frac{3}{10} \times 40 = 12.
5
Find the distance OPOP between point PP and the intersection point OO.
OP=8OP = 8.
Since AO=20AO = 20 and PP is 1212 units from AA, PP lies on the segment AOAO. Thus, the distance from PP to OO is OP=AOAP=2012=8OP = AO - AP = 20 - 12 = 8.
6
Calculate the length of segment BPBP.
BP=17BP = 17.
Because the diagonals of a rhombus are perpendicular, BOP\triangle BOP is a right triangle with legs BO=15BO = 15 and OP=8OP = 8. Using the Pythagorean theorem, BP=BO2+OP2=152+82=17BP = \sqrt{BO^2 + OP^2} = \sqrt{15^2 + 8^2} = 17.

Anahtar Kavram

Properties of Rhombuses (perpendicular bisecting diagonals, equal side lengths) and the Pythagorean Theorem
Tahmini Süre:2m 0s
Soru 402Soru

In the standard (x,y)(x, y) coordinate plane, three vertices of a rectangle are A(4,1)A(-4, 1), B(2,9)B(2, 9), and C(6,6)C(6, 6). What is the area of the rectangle, in square units?

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Cevap: 50

Cevap

50
The length of side ABAB is calculated as (2(4))2+(91)2=36+64=10\sqrt{(2 - (-4))^2 + (9 - 1)^2} = \sqrt{36 + 64} = 10. The length of the adjacent side BCBC is calculated as (62)2+(69)2=16+9=5\sqrt{(6 - 2)^2 + (6 - 9)^2} = \sqrt{16 + 9} = 5. The area of the rectangle is the product of these two perpendicular side lengths, which is 10×5=5010 \times 5 = 50.

Adım Adım Çözüm

1
Calculate the length of side ABAB using the distance formula.
AB=10AB = 10
To find one of the side lengths of the rectangle.
2
Calculate the length of side BCBC using the distance formula.
BC=5BC = 5
To find the adjacent side length of the rectangle.
3
Multiply the two adjacent side lengths to find the area of the rectangle.
50
The area of a rectangle is equal to the product of its length and width.

Anahtar Kavram

Calculating the area of a geometric figure on the coordinate plane by determining its side lengths using the distance formula.
Soru 403Soru

For the quadratic equation 0.4x2+bx4.8=00.4x^2 + bx - 4.8 = 0, where bb is a constant, the sum of the two solutions is equal to the product of the two solutions. What is the value of bb?

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Cevap: 4.8

Cevap

The value of the constant bb is 4.84.8.
According to Vieta's formulas, the sum of the solutions to the quadratic equation ax2+bx+c=0ax^2 + bx + c = 0 is given by ba-\frac{b}{a} and their product is given by ca\frac{c}{a}. For the given equation 0.4x2+bx4.8=00.4x^2 + bx - 4.8 = 0, the product of the solutions is 4.80.4=12\frac{-4.8}{0.4} = -12. Setting the sum equal to the product yields the equation b0.4=12-\frac{b}{0.4} = -12. Multiplying both sides by 0.4-0.4 isolates bb, giving b=4.8b = 4.8.

Adım Adım Çözüm

1
Identify the coefficients of the quadratic equation.
a=0.4a = 0.4, b=bb = b, and c=4.8c = -4.8.
To apply formulas relating the coefficients to the solutions.
2
Express the sum and product of the solutions using Vieta's formulas.
Sum of solutions is b0.4-\frac{b}{0.4} and product of solutions is 4.80.4=12\frac{-4.8}{0.4} = -12.
To establish the mathematical relationship given in the problem.
3
Equate the sum and product of the solutions and solve for the constant bb.
b0.4=12    b=12×(0.4)=4.8-\frac{b}{0.4} = -12 \implies b = -12 \times (-0.4) = 4.8.
The problem states that the sum of the two solutions is equal to their product.

Anahtar Kavram

Sum and Product of Roots (Vieta's Formulas)
Soru 404Soru

In the standard (x,y)(x, y) coordinate plane, the vertices of a right triangle are P(1,2)P(1, 2), Q(5,5)Q(5, 5), and R(k,9)R(k, 9). If the right angle of the triangle is at vertex QQ, what is the value of the constant kk?

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Cevap: 2

Cevap

The value of kk is 22.
Because the right angle of the triangle is at vertex QQ, segment PQPQ must be perpendicular to segment QRQR. The slope of PQPQ is 5251=34\frac{5 - 2}{5 - 1} = \frac{3}{4}. The slope of a perpendicular line is the negative reciprocal, so the slope of QRQR must be 43-\frac{4}{3}. Expressing the slope of QRQR using the coordinates of Q(5,5)Q(5, 5) and R(k,9)R(k, 9) gives 95k5=4k5\frac{9 - 5}{k - 5} = \frac{4}{k - 5}. Setting this equal to 43-\frac{4}{3} and solving for kk yields k5=3k - 5 = -3, which means k=2k = 2.

Adım Adım Çözüm

1
Use the slope formula m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1} to calculate the slope of the line segment PQPQ with endpoints P(1,2)P(1, 2) and Q(5,5)Q(5, 5).
mPQ=5251=34m_{PQ} = \frac{5 - 2}{5 - 1} = \frac{3}{4}
This establishes the direction of the first leg of the right triangle.
2
Find the slope of segment QRQR. Because the right angle is at vertex QQ, the segment PQPQ is perpendicular to segment QRQR.
mQR=43m_{QR} = -\frac{4}{3}
Perpendicular lines have slopes that are negative reciprocals of each other (m1m2=1m_1 \cdot m_2 = -1).
3
Write the slope of segment QRQR in terms of kk using coordinates Q(5,5)Q(5, 5) and R(k,9)R(k, 9).
mQR=95k5=4k5m_{QR} = \frac{9 - 5}{k - 5} = \frac{4}{k - 5}
This sets up an equation to find the unknown coordinate value.
4
Equate the two expressions for the slope of QRQR and solve for kk.
4k5=43k5=3k=2\frac{4}{k - 5} = -\frac{4}{3} \Rightarrow k - 5 = -3 \Rightarrow k = 2
Solving the rational equation yields the correct coordinate parameter.

Anahtar Kavram

Perpendicular lines in a coordinate plane have slopes that are negative reciprocals of each other.
Tahmini Süre:1m 30s
Soru 405Soru

An angle θ\theta in standard position is rotated counterclockwise by 225225^\circ. The terminal ray of the resulting angle lies in the fourth quadrant along the line y=x3y = -x\sqrt{3}. If the radian measure of the smallest positive angle θ\theta is written in simplest form as aπb\frac{a\pi}{b}, where aa and bb are positive integers, what is the value of a+ba + b?

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Cevap: 17

Cevap

The value of a+ba + b is 1717.
The resulting angle α\alpha lies along the line y=x3y = -x\sqrt{3} in the fourth quadrant, meaning its measure is 300300^\circ plus any multiple of 360360^\circ. Subtracting the counterclockwise rotation of 225225^\circ gives the original angle θ=75\theta = 75^\circ (for the smallest positive angle). Converting 7575^\circ to radians by multiplying by π180\frac{\pi}{180^\circ} yields 5π12\frac{5\pi}{12}. Since the fraction is in simplest form, a=5a = 5 and b=12b = 12, and their sum is 1717.

Adım Adım Çözüm

1
Find the angle of the terminal ray after rotation from its equation and quadrant
The terminal ray after rotation is at an angle of 300300^\circ (or 5π3\frac{5\pi}{3} radians)
The line y=x3y = -x\sqrt{3} has a slope of 3-\sqrt{3}, so the angle α\alpha in Quadrant IV satisfies tanα=3\tan\alpha = -\sqrt{3}, which means α=300\alpha = 300^\circ.
2
Set up and solve the equation for the original angle θ\theta before the counterclockwise rotation of 225225^\circ
θ=75+360k\theta = 75^\circ + 360^\circ k
Since the angle was rotated counterclockwise by 225225^\circ to reach the final position of 300300^\circ, we have θ+225=300+360k\theta + 225^\circ = 300^\circ + 360^\circ k.
3
Determine the smallest positive value of θ\theta
θ=75\theta = 75^\circ
Setting k=0k = 0 gives the smallest positive angle of 7575^\circ.
4
Convert the angle θ\theta from degrees to radians
θ=5π12\theta = \frac{5\pi}{12} radians
To convert degrees to radians, multiply by π180\frac{\pi}{180^\circ}, yielding 75π180=5π12\frac{75\pi}{180} = \frac{5\pi}{12}.
5
Calculate the sum of the numerator and denominator of the simplified radian fraction
a+b=17a + b = 17
The fraction 512\frac{5}{12} is in simplest form, so a=5a = 5 and b=12b = 12. The sum is 5+12=175 + 12 = 17.

Anahtar Kavram

Converting degree measures to radian measures and finding coterminal angles on the unit circle
Soru 406Soru

A convex octagon has interior angles whose measures, in degrees, are eight consecutive even integers. What is the measure, in degrees, of the largest interior angle of this octagon?

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Cevap: 142

Cevap

The correct answer is 142.
The sum of the interior angles of a convex octagon is (82)×180=1080(8-2) \times 180^\circ = 1080^\circ. If we represent the eight consecutive even integer angle measures as x,x+2,x+4,x+6,x+8,x+10,x+12,x, x+2, x+4, x+6, x+8, x+10, x+12, and x+14x+14, their sum is 8x+568x + 56. Setting this equal to 10801080^\circ and solving for xx yields x=128x = 128. The largest angle is x+14x + 14, which equals 128+14=142128 + 14 = 142^\circ.

Adım Adım Çözüm

1
Calculate the sum of the interior angles of a convex octagon.
The sum of the interior angles is 10801080^\circ.
The formula for the sum of the interior angles of an nn-sided polygon is (n2)×180(n-2) \times 180^\circ. For an octagon (n=8n=8), the sum is (82)×180=6×180=1080(8-2) \times 180^\circ = 6 \times 180^\circ = 1080^\circ.
2
Set up an equation representing the sum of the eight consecutive even integer angle measures.
The equation is 8x+56=10808x + 56 = 1080.
Letting the smallest angle measure be xx, the eight consecutive even integer angle measures are x,x+2,x+4,x+6,x+8,x+10,x+12,x, x+2, x+4, x+6, x+8, x+10, x+12, and x+14x+14. Their sum is 8x+568x + 56, which must equal the total sum of the interior angles (10801080^\circ).
3
Solve the equation for the smallest angle measure, xx.
x=128x = 128
Subtracting 56 from both sides of the equation yields 8x=10248x = 1024. Dividing both sides by 8 gives x=128x = 128.
4
Calculate the measure of the largest interior angle.
The measure of the largest angle is 142142^\circ.
The largest angle is represented by the expression x+14x + 14. Substituting 128128 for xx gives 128+14=142128 + 14 = 142.

Anahtar Kavram

Calculating the sum of the interior angles of a convex polygon and using algebraic methods to find unknown angle measures.
Soru 407Soru

In the standard (x,y)(x, y) coordinate plane, a line passes through the points (a,2)(a, 2) and (10,a1)(10, a - 1). If the slope of the line is 13-\frac{1}{3}, what is the value of aa?

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Cevap: -0.5

Cevap

The value of aa is 0.5-0.5 (or 12-\frac{1}{2})
Applying the slope formula m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1} to the points (a,2)(a, 2) and (10,a1)(10, a - 1) with slope 13-\frac{1}{3} yields the equation 13=a310a-\frac{1}{3} = \frac{a - 3}{10 - a}. Solving this linear equation correctly yields a=0.5a = -0.5.

Adım Adım Çözüm

1
Apply the slope formula using the given coordinates.
13=(a1)210a-\frac{1}{3} = \frac{(a - 1) - 2}{10 - a}
The slope of a line passing through (x1,y1)(x_1, y_1) and (x2,y2)(x_2, y_2) is defined as m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1}.
2
Simplify the numerator.
13=a310a-\frac{1}{3} = \frac{a - 3}{10 - a}
Subtracting 22 from a1a - 1 simplifies the numerator to a3a - 3.
3
Cross-multiply to solve the rational equation.
1(10a)=3(a3)-1(10 - a) = 3(a - 3)
Multiplying both sides by the denominators eliminates the fractions.
4
Solve the linear equation for aa.
a=0.5a = -0.5
Distributing on both sides gives 10+a=3a9-10 + a = 3a - 9. Rearranging terms yields 2a=12a = -1, which simplifies to a=0.5a = -0.5.

Anahtar Kavram

Slope of a Line
Soru 408Soru

For an angle θ\theta in the interval 3π2<θ<2π\frac{3\pi}{2} < \theta < 2\pi, the expression secθtanθ\sec\theta - \tan\theta is equal to 33. What is the value of cscθ+cotθ\csc\theta + \cot\theta?

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Cevap: -2

Cevap

The value of cscθ+cotθ\csc\theta + \cot\theta is 2-2.
By using the difference of squares on the identity sec2θtan2θ=1\sec^2\theta - \tan^2\theta = 1, we get (secθtanθ)(secθ+tanθ)=1(\sec\theta - \tan\theta)(\sec\theta + \tan\theta) = 1. Substituting secθtanθ=3\sec\theta - \tan\theta = 3 gives secθ+tanθ=13\sec\theta + \tan\theta = \frac{1}{3}. Solving the system of equations gives secθ=53\sec\theta = \frac{5}{3} and tanθ=43\tan\theta = -\frac{4}{3}. Since θ\theta lies in Quadrant IV, cosθ=35\cos\theta = \frac{3}{5} and sinθ=45\sin\theta = -\frac{4}{5}. We then find cscθ=54\csc\theta = -\frac{5}{4} and cotθ=34\cot\theta = -\frac{3}{4}, which sum to 2-2.

Adım Adım Çözüm

1
Use the Pythagorean identity sec2θtan2θ=1\sec^2\theta - \tan^2\theta = 1, which factors into (secθtanθ)(secθ+tanθ)=1(\sec\theta - \tan\theta)(\sec\theta + \tan\theta) = 1.
Since secθtanθ=3\sec\theta - \tan\theta = 3, we have 3(secθ+tanθ)=1    secθ+tanθ=133(\sec\theta + \tan\theta) = 1 \implies \sec\theta + \tan\theta = \frac{1}{3}.
To establish a second linear equation in terms of secθ\sec\theta and tanθ\tan\theta.
2
Add and subtract the two equations: secθtanθ=3\sec\theta - \tan\theta = 3 and secθ+tanθ=13\sec\theta + \tan\theta = \frac{1}{3}.
Adding them gives 2secθ=103    secθ=532\sec\theta = \frac{10}{3} \implies \sec\theta = \frac{5}{3}. Subtracting the first from the second gives 2tanθ=83    tanθ=432\tan\theta = -\frac{8}{3} \implies \tan\theta = -\frac{4}{3}.
To isolate the values of secθ\sec\theta and tanθ\tan\theta.
3
Find cosθ\cos\theta and sinθ\sin\theta using cosθ=1secθ\cos\theta = \frac{1}{\sec\theta} and sinθ=tanθcosθ\sin\theta = \tan\theta\cos\theta.
cosθ=35\cos\theta = \frac{3}{5} and sinθ=45\sin\theta = -\frac{4}{5}. Since 3π2<θ<2π\frac{3\pi}{2} < \theta < 2\pi (Quadrant IV), cosine is positive and sine is negative, which matches these values.
To find the primary trigonometric values needed for the reciprocal functions.
4
Calculate cscθ\csc\theta and cotθ\cot\theta using reciprocal identities.
cscθ=1sinθ=54\csc\theta = \frac{1}{\sin\theta} = -\frac{5}{4} and cotθ=1tanθ=34\cot\theta = \frac{1}{\tan\theta} = -\frac{3}{4}.
To obtain the terms of the required sum.
5
Sum the values of cscθ\csc\theta and cotθ\cot\theta.
cscθ+cotθ=54+(34)=84=2\csc\theta + \cot\theta = -\frac{5}{4} + \left(-\frac{3}{4}\right) = -\frac{8}{4} = -2.
To obtain the final value requested by the question.

Anahtar Kavram

Pythagorean and Reciprocal Trigonometric Identities
Soru 409Soru

Three vertices of a parallelogram are A(1,3)A(1, 3), B(2,1)B(-2, -1), and C(4,1)C(4, -1) in the standard (x,y)(x, y) coordinate plane. If the fourth vertex, DD, is located in the fourth quadrant, what is the yy-coordinate of DD?

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Cevap: -5

Cevap

The yy-coordinate of the fourth vertex of the parallelogram in the fourth quadrant is 5-5.
By applying the midpoint formula to the diagonals of the three possible parallelograms formed by the vertices A(1,3)A(1, 3), B(2,1)B(-2, -1), and C(4,1)C(4, -1), we find the candidate points for the fourth vertex DD to be (7,3)(7, 3), (5,3)(-5, 3), and (1,5)(1, -5). The point (1,5)(1, -5) is the only candidate that lies in the fourth quadrant, where x>0x > 0 and y<0y < 0. Therefore, the yy-coordinate of the fourth vertex is 5-5.

Adım Adım Çözüm

1
Set up equations based on the property that the diagonals of a parallelogram bisect each other (have the same midpoint).
Three possible configurations of diagonals lead to three potential sets of coordinates for the fourth vertex D(x,y)D(x, y): (7,3)(7, 3), (5,3)(-5, 3), and (1,5)(1, -5).
Three points in a coordinate plane can form three distinct parallelograms depending on which pairs are connected as diagonals.
2
Identify the signs of the coordinates for each potential vertex to determine which quadrant it lies in.
The point (7,3)(7, 3) is in Quadrant I (x>0,y>0x > 0, y > 0). The point (5,3)(-5, 3) is in Quadrant II (x<0,y>0x < 0, y > 0). The point (1,5)(1, -5) is in Quadrant IV (x>0,y<0x > 0, y < 0).
The fourth quadrant is defined by positive xx-values and negative yy-values.
3
Select the correct coordinate value corresponding to the question's requirement.
The yy-coordinate of the vertex in the fourth quadrant, (1,5)(1, -5), is 5-5.
The question asks specifically for the yy-coordinate of the fourth vertex DD.

Anahtar Kavram

Finding a missing vertex of a parallelogram on the coordinate plane using midpoint properties
Soru 410Soru

In the standard (x,y)(x, y) coordinate plane, line L1L_1 passes through the points (1,3)(1, 3) and (4,8)(4, 8). Line L2L_2 is perpendicular to line L1L_1. If line L2L_2 passes through the points (5,k)(5, k) and (10,1)(10, 1), what is the value of kk?

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Cevap: 4

Cevap

The value of kk is 44.
The correct answer is 44. First, determine the slope of line L1L_1 using the points (1,3)(1, 3) and (4,8)(4, 8), which is 8341=53\frac{8 - 3}{4 - 1} = \frac{5}{3}. Because line L2L_2 is perpendicular to L1L_1, its slope must be the negative reciprocal of 53\frac{5}{3}, which is 35-\frac{3}{5}. Next, set up the slope equation for L2L_2 with the points (5,k)(5, k) and (10,1)(10, 1), yielding 1k105=35\frac{1 - k}{10 - 5} = -\frac{3}{5}. Simplifying the equation gives 1k5=35\frac{1 - k}{5} = -\frac{3}{5}, which reduces to 1k=31 - k = -3. Solving for kk gives k=4k = 4.

Adım Adım Çözüm

1
Calculate the slope of line L1L_1 using the coordinates of the two given points, (1,3)(1, 3) and (4,8)(4, 8).
The slope of line L1L_1 is 53\frac{5}{3}.
Using the slope formula m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1}, we find m1=8341=53m_1 = \frac{8 - 3}{4 - 1} = \frac{5}{3}.
2
Determine the slope of line L2L_2 based on the perpendicular relationship between L1L_1 and L2L_2.
The slope of line L2L_2 is 35-\frac{3}{5}.
Perpendicular lines have slopes that are negative reciprocals of each other. The negative reciprocal of 53\frac{5}{3} is 35-\frac{3}{5}.
3
Use the coordinates (5,k)(5, k) and (10,1)(10, 1) on line L2L_2 to write an expression for its slope, set it equal to 35-\frac{3}{5}, and solve for kk.
k=4k = 4
The slope expression is 1k105=1k5\frac{1 - k}{10 - 5} = \frac{1 - k}{5}. Setting this equal to the perpendicular slope gives 1k5=35\frac{1 - k}{5} = -\frac{3}{5}. Multiplying both sides by 55 results in 1k=31 - k = -3. Adding kk to both sides and adding 33 to both sides yields k=4k = 4.

Anahtar Kavram

The slopes of perpendicular lines in a coordinate plane are negative reciprocals of each other, meaning their product is 1-1 (m1m2=1m_1 \cdot m_2 = -1).
Tahmini Süre:1m 15s
Soru 411Soru

An architect is designing a triangular roof truss, ABC\triangle ABC, where side ABAB is equal in length to side ACAC. The height of the truss, represented by the altitude from vertex AA to the base BCBC, is 1212 feet. If the measure of the base angle ABC\angle ABC is 3030^\circ, what is the length, in feet, of the base BCBC? (Round your answer to the nearest tenth.)

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Cevap: 41.6

Cevap

The correct answer is 41.6
The correct answer is obtained by recognizing that the altitude of the isosceles triangle bisects the base into two congruent 30609030^\circ-60^\circ-90^\circ right triangles. The leg opposite the 3030^\circ angle is 1212 feet, so the leg adjacent (which is half the base) is 12312\sqrt{3} feet. Doubling this gives a total base length of 24324\sqrt{3} feet, which is approximately 41.641.6 feet when rounded to the nearest tenth.

Adım Adım Çözüm

1
Identify the right triangle formed by the altitude.
An altitude ADAD perpendicular to base BCBC, creating two right triangles, ABD\triangle ABD and ACD\triangle ACD, with AD=12AD = 12 feet.
In an isosceles triangle, the altitude to the base bisects the base and is perpendicular to it.
2
Determine the angles of the right triangle ABD\triangle ABD.
Triangle ABD\triangle ABD is a 30609030^\circ-60^\circ-90^\circ special right triangle.
Angle BB is 3030^\circ and angle ADBADB is 9090^\circ, leaving 6060^\circ for angle BADBAD.
3
Calculate the length of the segment BDBD.
BD=123BD = 12\sqrt{3} feet
In a 30609030^\circ-60^\circ-90^\circ triangle, the longer leg is 3\sqrt{3} times the shorter leg (which is opposite the 3030^\circ angle).
4
Find the total length of the base BCBC.
BC=243BC = 24\sqrt{3} feet
Since DD is the midpoint of BCBC, the total length BCBC is 2×BD2 \times BD.
5
Convert the exact value to a decimal rounded to the nearest tenth.
BC41.6BC \approx 41.6
24×1.73205=41.56924 \times 1.73205 = 41.569, which rounds to 41.641.6.

Anahtar Kavram

Properties of special 30-60-90 right triangles and altitudes of isosceles triangles
Soru 412Soru

An angle θ\theta lies in the third quadrant, where π<θ<3π2\pi < \theta < \frac{3\pi}{2}. If sinθcosθ=15\sin\theta - \cos\theta = -\frac{1}{5}, what is the value of the expression 125(sin3θ+cos3θ)125(\sin^3\theta + \cos^3\theta)?

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Cevap: -91

Cevap

The correct value of the expression is -91.
Squaring the equation sinθcosθ=15\sin\theta - \cos\theta = -\frac{1}{5} gives 12sinθcosθ=1251 - 2\sin\theta\cos\theta = \frac{1}{25}, which simplifies to sinθcosθ=1225\sin\theta\cos\theta = \frac{12}{25}. We then find the square of the sum: (sinθ+cosθ)2=1+2sinθcosθ=1+2425=4925(\sin\theta + \cos\theta)^2 = 1 + 2\sin\theta\cos\theta = 1 + \frac{24}{25} = \frac{49}{25}. Since the angle is in the third quadrant, both trigonometric functions are negative, so we choose the negative root sinθ+cosθ=75\sin\theta + \cos\theta = -\frac{7}{5}. Factoring the sum of cubes gives sin3θ+cos3θ=(sinθ+cosθ)(sin2θsinθcosθ+cos2θ)=(75)(11225)=91125\sin^3\theta + \cos^3\theta = (\sin\theta + \cos\theta)(\sin^2\theta - \sin\theta\cos\theta + \cos^2\theta) = (-\frac{7}{5})(1 - \frac{12}{25}) = -\frac{91}{125}. Multiplying this by 125 yields -91.

Adım Adım Çözüm

1
Square both sides of the equation sinθcosθ=15\sin\theta - \cos\theta = -\frac{1}{5}
sin2θ2sinθcosθ+cos2θ=125    12sinθcosθ=125    sinθcosθ=1225\sin^2\theta - 2\sin\theta\cos\theta + \cos^2\theta = \frac{1}{25} \implies 1 - 2\sin\theta\cos\theta = \frac{1}{25} \implies \sin\theta\cos\theta = \frac{12}{25}
To solve for the product of sine and cosine using the Pythagorean identity sin2θ+cos2θ=1\sin^2\theta + \cos^2\theta = 1.
2
Determine the value of sinθ+cosθ\sin\theta + \cos\theta using the identity (sinθ+cosθ)2=1+2sinθcosθ(\sin\theta + \cos\theta)^2 = 1 + 2\sin\theta\cos\theta
(sinθ+cosθ)2=1+2(1225)=4925    sinθ+cosθ=75(\sin\theta + \cos\theta)^2 = 1 + 2(\frac{12}{25}) = \frac{49}{25} \implies \sin\theta + \cos\theta = -\frac{7}{5}
Because θ\theta is in the third quadrant (π<θ<3π2\pi < \theta < \frac{3\pi}{2}), both sinθ\sin\theta and cosθ\cos\theta must be negative, meaning their sum is also negative.
3
Use the sum of cubes factorization to evaluate sin3θ+cos3θ\sin^3\theta + \cos^3\theta
sin3θ+cos3θ=(sinθ+cosθ)(sin2θsinθcosθ+cos2θ)=(75)(11225)=91125\sin^3\theta + \cos^3\theta = (\sin\theta + \cos\theta)(\sin^2\theta - \sin\theta\cos\theta + \cos^2\theta) = (-\frac{7}{5})(1 - \frac{12}{25}) = -\frac{91}{125}
To express the sum of cubes in terms of the known sum and product of sine and cosine.
4
Multiply the evaluated sum of cubes by 125
125×(91125)=91125 \times (-\frac{91}{125}) = -91
To compute the final value of the requested expression.

Anahtar Kavram

Pythagorean trigonometric identities, quadrant sign analysis, and algebraic factorization of the sum of cubes

Alternatif Yöntem

Instead of applying algebraic identities to find the sum of cubes directly, we can solve for the individual values of sinθ\sin\theta and cosθ\cos\theta from the system of equations: sinθcosθ=15\sin\theta - \cos\theta = -\frac{1}{5} and sin2θ+cos2θ=1\sin^2\theta + \cos^2\theta = 1. Substituting sinθ=cosθ15\sin\theta = \cos\theta - \frac{1}{5} into the second equation yields 2cos2θ25cosθ2425=02\cos^2\theta - \frac{2}{5}\cos\theta - \frac{24}{25} = 0, which factors as (5cosθ+3)(5cosθ4)=0(5\cos\theta + 3)(5\cos\theta - 4) = 0. Since θ\theta is in Quadrant III, cosθ=35\cos\theta = -\frac{3}{5} and sinθ=45\sin\theta = -\frac{4}{5}. Evaluating 125(sin3θ+cos3θ)125(\sin^3\theta + \cos^3\theta) directly with these values gives 125((45)3+(35)3)=125(6412527125)=91125((-\frac{4}{5})^3 + (-\frac{3}{5})^3) = 125(-\frac{64}{125} - \frac{27}{125}) = -91.
Tahmini Süre:2m 30s
Soru 413Soru

Chords ABAB and CDCD intersect at point EE inside a circle. If AE=6AE = 6, EB=8EB = 8, and the total length of chord CDCD is 1616, what is the length of the shorter segment of chord CDCD?

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Cevap: 4

Cevap

The length of the shorter segment of chord CDCD is 44.
According to the Intersecting Chords Theorem, when two chords intersect inside a circle, the product of the segments of one chord is equal to the product of the segments of the other. For chords ABAB and CDCD intersecting at point EE, this relationship is expressed as AEEB=CEEDAE \cdot EB = CE \cdot ED. Substituting the given values yields 68=CEED6 \cdot 8 = CE \cdot ED, so CEED=48CE \cdot ED = 48. Since the total length of chord CDCD is 1616, we can define CE=xCE = x and ED=16xED = 16 - x. The equation becomes x(16x)=48x(16 - x) = 48, which simplifies to the quadratic equation x216x+48=0x^2 - 16x + 48 = 0. Factoring this equation gives (x12)(x4)=0(x - 12)(x - 4) = 0, meaning the two segments of chord CDCD have lengths of 1212 and 44. The length of the shorter segment is 44.

Adım Adım Çözüm

1
State the relationship between intersecting chord segments.
AEEB=CEEDAE \cdot EB = CE \cdot ED
By the Intersecting Chords Theorem, the product of the segments of one chord equals the product of the segments of the other.
2
Substitute the known lengths and define the segments of CDCD using a variable xx.
68=x(16x)6 \cdot 8 = x(16 - x), which simplifies to 48=16xx248 = 16x - x^2.
We are given AE=6AE = 6 and EB=8EB = 8. Since the total length of chord CDCD is 1616, if one segment is xx, the remaining segment must be 16x16 - x.
3
Solve the quadratic equation for xx by factoring.
x216x+48=0    (x12)(x4)=0x^2 - 16x + 48 = 0 \implies (x - 12)(x - 4) = 0, so x=12x = 12 or x=4x = 4.
Rearranging the equation into standard quadratic form allows us to find the two possible segment lengths.
4
Identify the shorter segment length from the two solutions.
44
The two segment lengths are 1212 and 44. The problem asks for the shorter segment, which is 44.

Anahtar Kavram

Intersecting Chords Theorem
Soru 414Soru

In triangle ABCABC, the length of side aa is 55 centimeters, the length of side bb is 88 centimeters, and the measure of angle CC is 6060^\circ. What is the length, in centimeters, of side cc?

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Cevap: 7

Cevap

The length of side cc is 77 centimeters.
Applying the Law of Cosines directly to the given Side-Angle-Side (SAS) triangle yields c2=52+822(5)(8)cos60=25+6440=49c^2 = 5^2 + 8^2 - 2(5)(8) \cos 60^\circ = 25 + 64 - 40 = 49, which gives c=7c = 7.

Adım Adım Çözüm

1
Identify the given values and the appropriate formula.
We are given two sides, a=5a = 5 and b=8b = 8, and the included angle C=60C = 60^\circ. To find the opposite side cc, we use the Law of Cosines: c2=a2+b22abcosCc^2 = a^2 + b^2 - 2ab \cos C.
The Law of Cosines relates three sides of a triangle to the cosine of one of its angles, which is applicable for Side-Angle-Side (SAS) configurations.
2
Substitute the known values into the Law of Cosines equation.
c2=52+822(5)(8)cos60c^2 = 5^2 + 8^2 - 2(5)(8) \cos 60^\circ
Plugging the given values into the formula allows us to solve for the unknown side cc.
3
Evaluate the trigonometric and arithmetic terms.
Since cos60=0.5\cos 60^\circ = 0.5, we get:
c2=25+6480(0.5)c^2 = 25 + 64 - 80(0.5)
c2=8940c^2 = 89 - 40
c2=49c^2 = 49
Simplifying the expression step-by-step leads to the value of c2c^2.
4
Take the square root of both sides to find the side length.
c=49=7c = \sqrt{49} = 7
Since side lengths must be positive, the square root of 4949 gives the exact length of side cc.

Anahtar Kavram

Law of Cosines
Soru 415Soru

In the figure, point BB lies on the line segment ACAC, and segment BDBD is perpendicular to ACAC. Triangle ABDABD is a right triangle with hypotenuse AD=8AD = 8 and ADB=30\angle ADB = 30^\circ. If the length of segment BCBC is 1111, what is the length of segment CDCD?

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Cevap: 13

Cevap

The length of segment CDCD is 1313.
The length of segment CDCD is 1313. Since BDBD is perpendicular to segment ACAC at point BB, ABD\triangle ABD and DBC\triangle DBC are both right triangles. In the 30609030^\circ-60^\circ-90^\circ right triangle ABD\triangle ABD, the hypotenuse is AD=8AD = 8, so the longer leg opposite the 6060^\circ angle is BD=43BD = 4\sqrt{3}. In right triangle DBC\triangle DBC, using the Pythagorean Theorem: CD2=BD2+BC2=(43)2+112=48+121=169CD^2 = BD^2 + BC^2 = (4\sqrt{3})^2 + 11^2 = 48 + 121 = 169. Taking the square root gives CD=13CD = 13.

Adım Adım Çözüm

1
Find the length of the shared perpendicular segment BDBD using the properties of the special 30609030^\circ-60^\circ-90^\circ right triangle ABD\triangle ABD.
BD=43BD = 4\sqrt{3}
In a 30609030^\circ-60^\circ-90^\circ right triangle, the side opposite the 6060^\circ angle is 32\frac{\sqrt{3}}{2} times the hypotenuse.
2
Apply the Pythagorean Theorem to right triangle DBC\triangle DBC to calculate the length of hypotenuse CDCD.
CD=13CD = 13
The Pythagorean Theorem states that the square of the hypotenuse is equal to the sum of the squares of the legs (CD2=BD2+BC2CD^2 = BD^2 + BC^2).

Anahtar Kavram

Solving for unknown sides in adjacent right triangles by combining special right triangle ratios (30609030^\circ-60^\circ-90^\circ) and the Pythagorean Theorem.
Soru 416Soru

In the standard (x,y)(x, y) coordinate plane, a parallelogram ABCDABCD has vertices A(6,3)A(-6, -3), B(1,3)B(1, -3), C(6,2)C(6, 2), and D(1,2)D(-1, 2). What is the length of the diagonal ACAC?

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Cevap: 13

Cevap

The correct answer is 13.
The length of the diagonal ACAC is found by calculating the distance between the vertices A(6,3)A(-6, -3) and C(6,2)C(6, 2). Using the distance formula: AC=(6(6))2+(2(3))2=122+52=144+25=169=13AC = \sqrt{(6 - (-6))^2 + (2 - (-3))^2} = \sqrt{12^2 + 5^2} = \sqrt{144 + 25} = \sqrt{169} = 13.

Adım Adım Çözüm

1
Identify the coordinates of the endpoints of diagonal ACAC.
A(6,3)A(-6, -3) and C(6,2)C(6, 2)
The diagonal of a polygon connects non-adjacent vertices, so the diagonal ACAC connects vertex AA to vertex CC.
2
Use the distance formula to find the length of the segment ACAC.
AC=(6(6))2+(2(3))2AC = \sqrt{(6 - (-6))^2 + (2 - (-3))^2}
The distance formula calculates the straight-line distance between two points on the coordinate plane.
3
Simplify the expression to find the final integer length.
1313
Calculating the squares and summing them gives 122+52=144+25=169=13\sqrt{12^2 + 5^2} = \sqrt{144 + 25} = \sqrt{169} = 13.

Anahtar Kavram

Calculating the length of a geometric segment on the coordinate plane using the distance formula.
Soru 417Soru

An angle θ\theta in standard position measures 750-750^\circ. Let ϕ\phi be the coterminal angle of θ\theta such that 0ϕ<2π0 \le \phi < 2\pi radians. If ϕ=aπb\phi = \frac{a\pi}{b}, where aa and bb are positive integers with no common factors, what is the value of a+ba + b?

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Cevap: 17

Cevap

17
To find the coterminal angle ϕ\phi in the range [0,2π)[0, 2\pi) radians, we first determine the coterminal angle in degrees by adding multiples of 360360^\circ. Adding 3×360=10803 \times 360^\circ = 1080^\circ to 750-750^\circ results in 330330^\circ. We then convert 330330^\circ to radians by multiplying by π180\frac{\pi}{180^\circ}, which simplifies to 11π6\frac{11\pi}{6}. Since 1111 and 66 are positive integers with no common factors, a=11a = 11 and b=6b = 6. The sum a+ba + b is 11+6=1711 + 6 = 17.

Adım Adım Çözüm

1
Find the positive coterminal angle of 750-750^\circ within one full rotation.
330330^\circ
Adding 10801080^\circ (three full rotations of 360360^\circ) to 750-750^\circ brings the angle within the standard range of [0,360)[0^\circ, 360^\circ).
2
Convert the angle from degrees to radians.
11π6\frac{11\pi}{6} radians
Multiplying the degree measure by π180\frac{\pi}{180^\circ} and simplifying the fraction converts it to radians.
3
Identify the values of aa and bb and compute their sum.
1717
Comparing 11π6\frac{11\pi}{6} to aπb\frac{a\pi}{b} shows a=11a = 11 and b=6b = 6, which share no common factors. Their sum is 11+6=1711 + 6 = 17.

Anahtar Kavram

Finding coterminal angles and converting angle measures between degrees and radians.
Tahmini Süre:1m 30s
Soru 418Soru

A line graphed on the standard (x,y)(x, y) coordinate plane has a slope of 0.50.5 and passes through the points (p,3)(p, 3) and (7,2p1)(7, 2p - 1). What is the value of pp?

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Cevap: 3

Cevap

The value of pp is 33.
Applying the slope formula m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1} to the points (p,3)(p, 3) and (7,2p1)(7, 2p - 1) with m=0.5m = 0.5 yields the linear equation 0.5=2p47p0.5 = \frac{2p - 4}{7 - p}. Cross-multiplying and solving for pp gives p=3p = 3.

Adım Adım Çözüm

1
Set up the slope formula using the given points and slope.
0.5=(2p1)37p0.5 = \frac{(2p - 1) - 3}{7 - p}
The slope of a line passing through (x1,y1)(x_1, y_1) and (x2,y2)(x_2, y_2) is given by the formula m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1}.
2
Simplify the numerator of the fraction.
0.5=2p47p0.5 = \frac{2p - 4}{7 - p}
Combine the constant terms 1-1 and 3-3 in the numerator.
3
Multiply both sides by the denominator to clear the fraction.
0.5(7p)=2p40.5(7 - p) = 2p - 4
Eliminating the denominator allows solving the linear equation.
4
Distribute the 0.50.5 on the left side of the equation.
3.50.5p=2p43.5 - 0.5p = 2p - 4
Multiply each term inside the parentheses by 0.50.5.
5
Isolate the variable pp by rearranging terms.
2.5p=7.52.5p = 7.5
Add 0.5p0.5p to both sides and add 44 to both sides.
6
Divide by the coefficient of pp to solve for pp.
p=3p = 3
Dividing 7.57.5 by 2.52.5 yields the final value of the parameter.

Anahtar Kavram

Calculating a parameter using the slope formula

Alternatif Yöntem

Instead of using the decimal 0.50.5, write it as the fraction 12\frac{1}{2}. The equation becomes 12=2p47p\frac{1}{2} = \frac{2p - 4}{7 - p}. Cross-multiplying gives 1(7p)=2(2p4)7p=4p815=5pp=31(7 - p) = 2(2p - 4) \Rightarrow 7 - p = 4p - 8 \Rightarrow 15 = 5p \Rightarrow p = 3.
Tahmini Süre:1m 30s
Soru 419Soru

A surveyor is measuring a triangular plot of land, ABCABC. The distance from point AA to point CC is 1212 meters, and the distance from point BB to point CC is 626\sqrt{2} meters. If the measure of angle BACBAC is 3030^\circ, what is the measure, in degrees, of the acute angle ABCABC?

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Cevap: 45

Cevap

The measure of the acute angle ABCABC is 4545 degrees.
Applying the Law of Sines yields the relation sin(B)12=sin(30)62\frac{\sin(B)}{12} = \frac{\sin(30^\circ)}{6\sqrt{2}}. Solving for sin(B)\sin(B) yields sin(B)=22\sin(B) = \frac{\sqrt{2}}{2}. Because the question specifies that the angle is acute, the measure of the angle is 4545^\circ.

Adım Adım Çözüm

1
Set up the Law of Sines relationship for triangle ABCABC using the side opposite angle BB (ACAC) and the side opposite angle AA (BCBC).
sin(B)AC=sin(A)BC\frac{\sin(B)}{AC} = \frac{\sin(A)}{BC}
The Law of Sines states that the ratio of the sine of an angle to the length of its opposite side is constant for all three angles in a triangle.
2
Substitute the given values into the equation: AC=12AC = 12, BC=62BC = 6\sqrt{2}, and A=30A = 30^\circ.
sin(B)12=sin(30)62\frac{\sin(B)}{12} = \frac{\sin(30^\circ)}{6\sqrt{2}}
This allows us to solve for the single unknown variable, the sine of angle BB.
3
Simplify the expression using the trigonometric value sin(30)=0.5\sin(30^\circ) = 0.5 and isolate sin(B)\sin(B).
sin(B)=120.562=662=12=22\sin(B) = \frac{12 \cdot 0.5}{6\sqrt{2}} = \frac{6}{6\sqrt{2}} = \frac{1}{\sqrt{2}} = \frac{\sqrt{2}}{2}
Simplifying the fractions helps us identify the standard trigonometric value.
4
Find the acute angle BB whose sine value is 22\frac{\sqrt{2}}{2}.
B=45B = 45^\circ
The inverse sine of 22\frac{\sqrt{2}}{2} for an acute angle is 4545^\circ.

Anahtar Kavram

Law of Sines
Tahmini Süre:1m 0s
Soru 420Soru

An angle θ\theta is positioned in the second quadrant. If the trigonometric expression cscθcotθ\csc\theta - \cot\theta is equal to 44, what is the value of 17cosθ17\cos\theta?

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Cevap: -15

Cevap

The value of 17cosθ17\cos\theta is 15-15.
The correct value is 15-15. By using the difference of squares on the identity csc2θcot2θ=1\csc^2\theta - \cot^2\theta = 1, we establish that cscθ+cotθ=14\csc\theta + \cot\theta = \frac{1}{4}. Solving this system alongside cscθcotθ=4\csc\theta - \cot\theta = 4 yields cscθ=178\csc\theta = \frac{17}{8} and cotθ=158\cot\theta = -\frac{15}{8}. Since cosθ=cotθcscθ\cos\theta = \frac{\cot\theta}{\csc\theta}, we find cosθ=1517\cos\theta = -\frac{15}{17}, which means 17cosθ=1517\cos\theta = -15.

Adım Adım Çözüm

1
Use the Pythagorean identity linking cosecant and cotangent to find the sum of the terms.
cscθ+cotθ=14\csc\theta + \cot\theta = \frac{1}{4}
Since csc2θcot2θ=1\csc^2\theta - \cot^2\theta = 1, factoring as a difference of squares gives (cscθcotθ)(cscθ+cotθ)=1(\csc\theta - \cot\theta)(\csc\theta + \cot\theta) = 1. Substituting cscθcotθ=4\csc\theta - \cot\theta = 4 yields 4(cscθ+cotθ)=14(\csc\theta + \cot\theta) = 1, so cscθ+cotθ=14\csc\theta + \cot\theta = \frac{1}{4}.
2
Solve the system of equations for cscθ\csc\theta and cotθ\cot\theta.
cscθ=178\csc\theta = \frac{17}{8} and cotθ=158\cot\theta = -\frac{15}{8}
Adding the equations cscθcotθ=4\csc\theta - \cot\theta = 4 and cscθ+cotθ=14\csc\theta + \cot\theta = \frac{1}{4} gives 2cscθ=174    cscθ=1782\csc\theta = \frac{17}{4} \implies \csc\theta = \frac{17}{8}. Subtracting the first equation from the second gives 2cotθ=154    cotθ=1582\cot\theta = -\frac{15}{4} \implies \cot\theta = -\frac{15}{8}.
3
Determine the value of cosθ\cos\theta using reciprocal and quotient identities.
cosθ=1517\cos\theta = -\frac{15}{17}
Using the relationship cosθ=cotθcscθ\cos\theta = \frac{\cot\theta}{\csc\theta}, we substitute the values to find cosθ=15/817/8=1517\cos\theta = \frac{-15/8}{17/8} = -\frac{15}{17}.
4
Calculate the final required expression value.
17cosθ=1517\cos\theta = -15
Multiplying the calculated value of cosθ\cos\theta by 1717 gives 17(1517)=1517 \left(-\frac{15}{17}\right) = -15.

Anahtar Kavram

Using fundamental Pythagorean, reciprocal, and quotient trigonometric identities to solve systems of equations and evaluate trigonometric expressions.
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