Tüm alıştırma soruları

5556 soru

Soru 2241Soru

In the standard (x,y)(x, y) coordinate plane, rectangle ABCDABCD has vertices A(3,1)A(-3, 1), B(1,1)B(-1, 1), C(1,4)C(-1, 4), and D(3,4)D(-3, 4). The rectangle is first reflected across the yy-axis and then translated 33 units to the left and 22 units down. What are the coordinates of the final image of vertex CC?

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Cevap: (2,2)(-2, 2)

Cevap

(2,2)(-2, 2)
To find the final image of vertex C(1,4)C(-1, 4), we first apply the reflection across the yy-axis. The rule for reflecting a point across the yy-axis is (x,y)(x,y)(x, y) \rightarrow (-x, y). Applying this to C(1,4)C(-1, 4) gives C(1,4)C'(1, 4). Next, we apply the translation of 33 units to the left and 22 units down. The rule for this translation is (x,y)(x3,y2)(x, y) \rightarrow (x - 3, y - 2). Applying this to C(1,4)C'(1, 4) gives C(13,42)=(2,2)C''(1 - 3, 4 - 2) = (-2, 2).

Adım Adım Çözüm

1
Identify the initial coordinates of vertex CC.
C(1,4)C(-1, 4)
We need to find the final image of vertex CC, so we start with its given coordinates.
2
Apply the reflection across the yy-axis to vertex CC.
C(1,4)C'(1, 4)
Reflecting a point (x,y)(x, y) across the yy-axis negates the x-coordinate, changing (x,y)(x, y) to (x,y)(-x, y).
3
Apply the translation of 33 units to the left and 22 units down to the reflected point CC'.
C(2,2)C''(-2, 2)
Translating a point (x,y)(x, y) by 33 units to the left subtracts 33 from the x-coordinate (x3x - 3), and translating 22 units down subtracts 22 from the y-coordinate (y2y - 2).

Anahtar Kavram

Composite transformations in the coordinate plane involve applying multiple geometric transformations in a specific sequence.
Soru 2242Soru

In the standard (x,y)(x, y) coordinate plane, line L1L_1 has a negative slope and passes through the point (1,4)(1, 4). Line L2L_2 has a positive slope and passes through the point (7,3)(7, 3). Both lines intersect the xx-axis at the same point PP. If the product of the slopes of L1L_1 and L2L_2 is 43-\frac{4}{3}, and line L3L_3 is perpendicular to L1L_1 and passes through the point (2,2)(2, -2), what is the yy-intercept of L3L_3?

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Cevap: -3.5

Cevap

The yy-intercept of line L3L_3 is 3.5-3.5.
By writing the slope of the first line as 4xp1\frac{-4}{x_p - 1} and the slope of the second line as 3xp7\frac{-3}{x_p - 7}, their product is set to 43-\frac{4}{3}. Solving the resulting quadratic equation (xp4)2=0(x_p - 4)^2 = 0 yields xp=4x_p = 4. Substituting this back gives a slope of 43-\frac{4}{3} for the first line. The perpendicular line must have a slope of 34\frac{3}{4}. Using the point-slope formula with point (2,2)(2, -2) and slope 34\frac{3}{4} gives the line y=34x3.5y = \frac{3}{4}x - 3.5, which crosses the yy-axis at 3.5-3.5.

Adım Adım Çözüm

1
Express the slopes of L1L_1 and L2L_2 in terms of the unknown xx-coordinate of point PP.
m1=04xp1=4xp1m_1 = \frac{0 - 4}{x_p - 1} = \frac{-4}{x_p - 1} and m2=03xp7=3xp7m_2 = \frac{0 - 3}{x_p - 7} = \frac{-3}{x_p - 7}
Since PP lies on the xx-axis, its coordinates are (xp,0)(x_p, 0). We apply the slope formula m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1} to the points on each line.
2
Set up the equation for the product of the slopes.
(4xp1)(3xp7)=43    12(xp1)(xp7)=43\left(\frac{-4}{x_p - 1}\right)\left(\frac{-3}{x_p - 7}\right) = -\frac{4}{3} \implies \frac{12}{(x_p - 1)(x_p - 7)} = -\frac{4}{3}
The problem states that the product of the slopes of L1L_1 and L2L_2 is 43-\frac{4}{3}.
3
Solve the equation for xpx_p.
xp=4x_p = 4
Cross-multiplying gives 36=4(xp28xp+7)36 = -4(x_p^2 - 8x_p + 7), which simplifies to 9=xp28xp+7    xp28xp+16=0    (xp4)2=0-9 = x_p^2 - 8x_p + 7 \implies x_p^2 - 8x_p + 16 = 0 \implies (x_p - 4)^2 = 0.
4
Find the slope of L1L_1.
m1=441=43m_1 = \frac{-4}{4 - 1} = -\frac{4}{3}
Substituting xp=4x_p = 4 back into the expression for m1m_1 yields the slope of L1L_1.
5
Find the slope of L3L_3.
m3=34m_3 = \frac{3}{4}
Since L3L_3 is perpendicular to L1L_1, its slope is the negative reciprocal of m1m_1.
6
Write the linear equation for L3L_3 and determine its yy-intercept.
y=34x3.5y = \frac{3}{4}x - 3.5, so the yy-intercept is 3.5-3.5.
Using the point-slope form with point (2,2)(2, -2) and slope m3=34m_3 = \frac{3}{4}, we get y(2)=34(x2)    y+2=34x1.5    y=34x3.5y - (-2) = \frac{3}{4}(x - 2) \implies y + 2 = \frac{3}{4}x - 1.5 \implies y = \frac{3}{4}x - 3.5.

Anahtar Kavram

The slope of a line is defined as m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1}. Perpendicular lines have slopes that are negative reciprocals of each other, satisfying m1m2=1m_1 \cdot m_2 = -1. The yy-intercept of a line is the value of yy when x=0x = 0.
Soru 2243Soru

In the standard (x,y)(x, y) coordinate plane, a line passes through the points (1,3)(1, 3) and (4,9)(4, 9). Is the statement that this line has a slope of 22 true or false?

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Cevap: True

Cevap

true
Applying the slope formula m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1} to the points (1,3)(1, 3) and (4,9)(4, 9) yields 9341=63=2\frac{9 - 3}{4 - 1} = \frac{6}{3} = 2, which confirms that the statement is true.

Adım Adım Çözüm

1
Identify the coordinates of the two points on the line.
The points are (x1,y1)=(1,3)(x_1, y_1) = (1, 3) and (x2,y2)=(4,9)(x_2, y_2) = (4, 9).
These coordinates are needed to apply the slope formula.
2
Apply the slope formula m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1} using the identified points.
m=9341=63=2m = \frac{9 - 3}{4 - 1} = \frac{6}{3} = 2.
This calculates the rate of change of the line, which is its slope.
3
Compare the calculated slope to the value in the statement.
The calculated slope is 22, which matches the statement.
To determine whether the statement is true or false.

Anahtar Kavram

The slope of a line is the ratio of the vertical change (rise) to the horizontal change (run) between any two points on the line.
Tahmini Süre:45s
Soru 2244Soru

In a coordinate plane, two perpendicular lines, L1L_1 and L2L_2, intersect at a point on the positive yy-axis. The line L1L_1 passes through the point (4,3)(-4, 3), and the line L2L_2 has an xx-intercept at (2.5,0)(2.5, 0). What is the yy-coordinate of the intersection point of L1L_1 and L2L_2?

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Cevap: 5

Cevap

The y-coordinate of the intersection point is 5.
The intersection point on the positive yy-axis has coordinates (0,5)(0, 5). The slope of the line passing through (4,3)(-4, 3) and (0,5)(0, 5) is 0.50.5. The slope of the line passing through (2.5,0)(2.5, 0) and (0,5)(0, 5) is 2-2. Since the product of these slopes is 0.5×(2)=10.5 \times (-2) = -1, the lines are perpendicular.

Adım Adım Çözüm

1
Identify the coordinates of the intersection point.
The intersection point of L1L_1 and L2L_2 is (0,b)(0, b), where b>0b > 0.
Since the intersection point lies on the positive yy-axis, its xx-coordinate is 00 and its yy-coordinate bb must be positive.
2
Calculate the slope of L1L_1.
The slope of L1L_1 is m1=b30(4)=b34m_1 = \frac{b - 3}{0 - (-4)} = \frac{b - 3}{4}.
The slope formula m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1} is applied to the points (4,3)(-4, 3) and (0,b)(0, b).
3
Calculate the slope of L2L_2.
The slope of L2L_2 is m2=b002.5=b2.5m_2 = \frac{b - 0}{0 - 2.5} = -\frac{b}{2.5}.
The line L2L_2 passes through the yy-intercept (0,b)(0, b) and its xx-intercept (2.5,0)(2.5, 0).
4
Apply the perpendicular slope condition.
m1m2=1    (b34)(b2.5)=1    b(b3)=10m_1 \cdot m_2 = -1 \implies \left(\frac{b - 3}{4}\right)\left(-\frac{b}{2.5}\right) = -1 \implies b(b - 3) = 10.
Perpendicular lines have slopes that are negative reciprocals of each other, meaning their product is 1-1.
5
Solve the quadratic equation for bb.
Expanding the equation gives b23b10=0b^2 - 3b - 10 = 0, which factors into (b5)(b+2)=0(b - 5)(b + 2) = 0. Since b>0b > 0, the only valid solution is b=5b = 5.
Solving the factored equation yields b=5b = 5 or b=2b = -2. The constraint that the intersection lies on the positive yy-axis rules out the negative value.

Anahtar Kavram

Perpendicular line slopes and coordinate intercepts
Tahmini Süre:2m 30s
Soru 2245Soru

For all real numbers xx and yy such that x>y>0x > y > 0, which of the following expressions is equivalent to log5(x2y2)log5(xy)\log_5(x^2 - y^2) - \log_5(x - y)?

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Cevap: log5(x+y)\log_5(x+y)

Cevap

The expression is equivalent to \log_5(x + y)
The correct answer is found by using the quotient property of logarithms to combine the terms: log5(x2y2)log5(xy)=log5(x2y2xy)\log_5(x^2 - y^2) - \log_5(x - y) = \log_5\left(\frac{x^2 - y^2}{x - y}\right). Factoring the difference of squares in the numerator yields log5((xy)(x+y)xy)\log_5\left(\frac{(x-y)(x+y)}{x-y}\right). Canceling the common factor (xy)(x-y) simplifies the expression to log5(x+y)\log_5(x+y).

Adım Adım Çözüm

1
Combine the logarithms using the quotient property of logarithms: logb(A)logb(B)=logb(AB)\log_b(A) - \log_b(B) = \log_b\left(\frac{A}{B}\right).
log5(x2y2xy)\log_5\left(\frac{x^2 - y^2}{x - y}\right)
This simplifies the difference between two logarithms with the same base into a single logarithm.
2
Factor the difference of squares in the numerator: x2y2=(xy)(x+y)x^2 - y^2 = (x - y)(x + y).
log5((xy)(x+y)xy)\log_5\left(\frac{(x - y)(x + y)}{x - y}\right)
This allows for the cancellation of common factors in the fraction.
3
Cancel the common factor (xy)(x - y) from both the numerator and the denominator.
log5(x+y)\log_5(x + y)
Since x>y>0x > y > 0, the term xyx - y is non-zero, making the division valid.

Anahtar Kavram

Quotient property of logarithms and difference of squares factoring

Alternatif Yöntem

Instead of applying the quotient property first, one can factor the argument of the first term using the difference of squares: log5(x2y2)=log5((xy)(x+y))\log_5(x^2 - y^2) = \log_5((x - y)(x + y)). Next, apply the product property of logarithms to split this term: log5(xy)+log5(x+y)\log_5(x - y) + \log_5(x + y). Substituting this back into the original expression gives log5(xy)+log5(x+y)log5(xy)\log_5(x - y) + \log_5(x + y) - \log_5(x - y), which simplifies directly to log5(x+y)\log_5(x + y).
Tahmini Süre:1m 0s
Soru 2246Soru

In the standard (x,y)(x, y) coordinate plane, the midpoint of the line segment with endpoints A(2,a)A(2, a) and B(b,3)B(b, -3) lies on the line y=3x4y = 3x - 4. If the distance between AA and BB is 525\sqrt{2} and a>0a > 0, what is the value of a+ba + b?

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Cevap: 5

Cevap

The value of a+ba + b is 55.
The midpoint of the segment with endpoints (2,a)(2, a) and (b,3)(b, -3) is (2+b2,a32)\left(\frac{2+b}{2}, \frac{a-3}{2}\right). Substituting these coordinates into the line y=3x4y = 3x - 4 gives a32=3(2+b2)4\frac{a-3}{2} = 3\left(\frac{2+b}{2}\right) - 4, which simplifies to a=3b+1a = 3b + 1. The squared distance between the endpoints is (b2)2+(3a)2=(52)2=50(b-2)^2 + (-3-a)^2 = (5\sqrt{2})^2 = 50. Substituting a=3b+1a = 3b + 1 into the distance equation yields (b2)2+(3b+4)2=50(b-2)^2 + (3b+4)^2 = 50, which simplifies to the quadratic equation b2+2b3=0b^2 + 2b - 3 = 0. Factoring gives (b+3)(b1)=0(b+3)(b-1) = 0, so b=1b = 1 or b=3b = -3. The constraint a>0a > 0 means a=3(1)+1=4a = 3(1) + 1 = 4 is the only valid solution. Therefore, the sum is 4+1=54 + 1 = 5.

Adım Adım Çözüm

1
Find the midpoint of the segment ABAB using the midpoint formula.
M=(2+b2,a32)M = \left(\frac{2+b}{2}, \frac{a-3}{2}\right)
The midpoint is defined as the average of the x-coordinates and the average of the y-coordinates.
2
Substitute the midpoint coordinates into the equation of the line y=3x4y = 3x - 4 to relate aa and bb.
a=3b+1a = 3b + 1
Since the midpoint lies on the line, its coordinates must satisfy the line's equation.
3
Use the distance formula to set up an equation for the distance between AA and BB.
(b2)2+(a+3)2=50(b-2)^2 + (a+3)^2 = 50
The squared distance between (2,a)(2, a) and (b,3)(b, -3) is (52)2=50(5\sqrt{2})^2 = 50.
4
Substitute the relation a=3b+1a = 3b + 1 into the distance equation and solve for bb.
b=1b = 1 or b=3b = -3
This yields the quadratic equation b2+2b3=0b^2 + 2b - 3 = 0, which factors as (b+3)(b1)=0(b+3)(b-1) = 0.
5
Apply the constraint a>0a > 0 to find the correct values of aa and bb.
a=4a = 4 and b=1b = 1
If b=3b = -3, then a=3(3)+1=8a = 3(-3) + 1 = -8, which is not greater than 00. If b=1b = 1, then a=3(1)+1=4>0a = 3(1) + 1 = 4 > 0.
6
Calculate the sum a+ba + b.
4+1=54 + 1 = 5
To find the final requested value.

Anahtar Kavram

Using the distance and midpoint formulas in combination with linear equations to solve for unknown coordinates.
Tahmini Süre:2m 30s
Soru 2247Soru

A circle in the standard (x,y)(x, y) coordinate plane is defined by the equation x2+y24x+6y12=0x^2 + y^2 - 4x + 6y - 12 = 0. What is the radius of this circle?

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Cevap: 55

Cevap

The radius of the circle is 5.
The correct answer is 5. Grouping the xx-terms and yy-terms of the equation x2+y24x+6y12=0x^2 + y^2 - 4x + 6y - 12 = 0 gives (x24x)+(y2+6y)=12(x^2 - 4x) + (y^2 + 6y) = 12. Completing the square requires adding (42)2=4(\frac{-4}{2})^2 = 4 and (62)2=9(\frac{6}{2})^2 = 9 to both sides, yielding (x24x+4)+(y2+6y+9)=12+4+9(x^2 - 4x + 4) + (y^2 + 6y + 9) = 12 + 4 + 9, which simplifies to (x2)2+(y+3)2=25(x-2)^2 + (y+3)^2 = 25. In the standard circle equation form (xh)2+(yk)2=r2(x-h)^2 + (y-k)^2 = r^2, r2=25r^2 = 25, meaning the radius rr is 25=5\sqrt{25} = 5.

Adım Adım Çözüm

1
Group the xx-terms and yy-terms, and move the constant term to the right side of the equation.
(x24x)+(y2+6y)=12(x^2 - 4x) + (y^2 + 6y) = 12
This prepares the quadratic expression to be written in standard circle form by completing the square.
2
Find the constant values needed to complete the square for both the xx and yy variables. Add these constants to both sides of the equation.
(x24x+4)+(y2+6y+9)=12+4+9(x^2 - 4x + 4) + (y^2 + 6y + 9) = 12 + 4 + 9
The constant for xx is (42)2=4(\frac{-4}{2})^2 = 4, and the constant for yy is (62)2=9(\frac{6}{2})^2 = 9. Adding them to both sides maintains equality.
3
Factor the perfect square trinomials on the left side and simplify the right side.
(x2)2+(y+3)2=25(x-2)^2 + (y+3)^2 = 25
This puts the equation in the standard form (xh)2+(yk)2=r2(x-h)^2 + (y-k)^2 = r^2.
4
Identify r2r^2 from the standard form and solve for the radius rr.
r=25=5r = \sqrt{25} = 5
Taking the square root of the constant on the right side yields the radius of the circle.

Anahtar Kavram

Rewriting a circle's equation from general form to standard form by completing the square to find its radius.

Alternatif Yöntem

For a circle given in the general form x2+y2+Dx+Ey+F=0x^2 + y^2 + Dx + Ey + F = 0, the radius can be calculated directly using the formula r=12D2+E24Fr = \frac{1}{2}\sqrt{D^2 + E^2 - 4F}. Substituting the coefficients D=4D = -4, E=6E = 6, and F=12F = -12 gives: r=12(4)2+624(12)=1216+36+48=12100=12(10)=5r = \frac{1}{2}\sqrt{(-4)^2 + 6^2 - 4(-12)} = \frac{1}{2}\sqrt{16 + 36 + 48} = \frac{1}{2}\sqrt{100} = \frac{1}{2}(10) = 5.
Tahmini Süre:1m 30s
Soru 2248Soru

In ABC\triangle ABC, the measure of interior angle A\angle A is 4545^\circ, and the exterior angle at vertex BB measures 125125^\circ. What is the measure, in degrees, of interior angle C\angle C?

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Cevap: 80

Cevap

The measure of interior angle C\angle C is 8080 degrees.
According to the Exterior Angle Theorem, the measure of an exterior angle of a triangle is equal to the sum of the measures of its two remote interior angles. In this case, the exterior angle at vertex BB measures 125125^\circ, and one of its remote interior angles, A\angle A, measures 4545^\circ. The other remote interior angle is C\angle C. Setting up the equation: 125=45+mC125^\circ = 45^\circ + \text{m}\angle C. Solving for the measure of C\angle C gives 12545=80125^\circ - 45^\circ = 80^\circ.

Adım Adım Çözüm

1
Use the Exterior Angle Theorem to relate the given angles.
The exterior angle at vertex BB (125125^\circ) is equal to the sum of the remote interior angles, A\angle A and C\angle C. This gives the equation: 125=45+mC125^\circ = 45^\circ + \text{m}\angle C.
The Exterior Angle Theorem states that the measure of an exterior angle of a triangle is equal to the sum of the measures of its two remote interior angles.
2
Solve the equation for the measure of C\angle C.
mC=12545=80\text{m}\angle C = 125^\circ - 45^\circ = 80^\circ
Subtract 4545^\circ from both sides of the equation to isolate the measure of C\angle C.

Anahtar Kavram

Exterior Angle Theorem
Soru 2249Soru

In the standard (x,y)(x, y) coordinate plane, line L1L_1 passes through the points (1,2)(-1, 2) and (3,14)(3, 14). If line L2L_2 is parallel to line L1L_1, what is the slope of line L2L_2?

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Cevap: 3

Cevap

The slope of line L2L_2 is 33.
To find the slope of line L2L_2, we calculate the slope of line L1L_1 using the formula m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1}. Substituting the coordinates (1,2)(-1, 2) and (3,14)(3, 14) yields m=1423(1)=124=3m = \frac{14 - 2}{3 - (-1)} = \frac{12}{4} = 3. Because parallel lines have the same slope, the slope of line L2L_2 is also 33.

Adım Adım Çözüm

1
Calculate the slope of line L1L_1 using the coordinates of the two given points, (1,2)(-1, 2) and (3,14)(3, 14).
m=3m = 3
The slope formula is m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1}, which evaluates to m=1423(1)=124=3m = \frac{14 - 2}{3 - (-1)} = \frac{12}{4} = 3.
2
Determine the slope of line L2L_2 based on its relationship to line L1L_1.
The slope of line L2L_2 is 33.
Parallel lines always have identical slopes.

Anahtar Kavram

Parallel lines have the same slope.
Soru 2250Soru

For all positive real numbers xx and yy, consider the algebraic expression:

((x+y)y2)1/2(x+y)2/3(x+y)1/2y\frac{\left((x + y)y^2\right)^{1/2} (x + y)^{2/3}}{(x + y)^{-1/2}y}

Which of the following is equivalent to this expression?

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Cevap: (x+y)5/3(x + y)^{5/3}

Cevap

(x+y)5/3(x + y)^{5/3}
The correct answer is obtained by applying the properties of exponents step-by-step. First, apply the power of a product rule to the term ((x+y)y2)1/2((x+y)y^2)^{1/2} to get (x+y)1/2y(x+y)^{1/2}y. Next, combine the terms in the numerator using the product rule of exponents to get (x+y)7/6y(x+y)^{7/6}y. Finally, divide by the denominator using the quotient rule of exponents, which cancels the yy terms and results in (x+y)5/3(x+y)^{5/3}.

Adım Adım Çözüm

1
Apply the power of a product property to simplify the first term in the numerator.
((x+y)y2)1/2=(x+y)1/2(y2)1/2=(x+y)1/2y\left((x + y)y^2\right)^{1/2} = (x + y)^{1/2}(y^2)^{1/2} = (x + y)^{1/2}y
To distribute the exponent 1/21/2 to each factor inside the parentheses.
2
Multiply the simplified term by the other factor in the numerator.
(x+y)1/2y(x+y)2/3=(x+y)1/2+2/3y=(x+y)7/6y(x + y)^{1/2}y \cdot (x + y)^{2/3} = (x + y)^{1/2 + 2/3}y = (x + y)^{7/6}y
To combine bases of the same value by adding their exponents: 12+23=36+46=76\frac{1}{2} + \frac{2}{3} = \frac{3}{6} + \frac{4}{6} = \frac{7}{6}.
3
Divide the simplified numerator by the denominator.
(x+y)7/6y(x+y)1/2y=(x+y)7/6(1/2)=(x+y)7/6+3/6=(x+y)10/6=(x+y)5/3\frac{(x + y)^{7/6}y}{(x + y)^{-1/2}y} = (x + y)^{7/6 - (-1/2)} = (x + y)^{7/6 + 3/6} = (x + y)^{10/6} = (x + y)^{5/3}
To subtract the exponent in the denominator from the exponent in the numerator and cancel the common factor yy.

Anahtar Kavram

Properties of Exponents in Algebraic Expressions

Alternatif Yöntem

Instead of simplifying the numerator first, we can divide the terms inside the parentheses first if we rewrite the expression, but the standard method of simplifying the numerator and then performing division is the most direct.
Tahmini Süre:1m 30s
Soru 2251Soru

If log2(x+5)+log2(x1)=4\log_2(x + 5) + \log_2(x - 1) = 4, what is the value of xx?

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Cevap: 3

Cevap

The correct answer is 3.
The correct answer is 3. Combining the logarithmic terms using the product property gives log2((x+5)(x1))=4\log_2((x + 5)(x - 1)) = 4. Converting this to exponential form yields (x+5)(x1)=24=16(x + 5)(x - 1) = 2^4 = 16. Expanding and rewriting in standard form gives x2+4x21=0x^2 + 4x - 21 = 0, which factors as (x+7)(x3)=0(x + 7)(x - 3) = 0. This gives potential solutions of x=3x = 3 and x=7x = -7. However, x=7x = -7 results in negative arguments for the logarithms in the original equation, making it extraneous. Thus, the only valid solution is 3.

Adım Adım Çözüm

1
Apply the product property of logarithms to combine the terms on the left side of the equation.
log2((x+5)(x1))=4\log_2((x + 5)(x - 1)) = 4
The sum of logarithms with the same base is equal to the logarithm of their product: logb(A)+logb(B)=logb(AB)\log_b(A) + \log_b(B) = \log_b(AB).
2
Convert the logarithmic equation to its equivalent exponential form.
(x+5)(x1)=24(x + 5)(x - 1) = 2^4
By definition, logb(Y)=C\log_b(Y) = C is equivalent to bC=Yb^C = Y.
3
Expand the product and simplify the equation into standard quadratic form.
x2+4x21=0x^2 + 4x - 21 = 0
Expanding (x+5)(x1)(x + 5)(x - 1) yields x2+4x5x^2 + 4x - 5. Subtracting 16 from both sides gives the standard quadratic form Ax2+Bx+C=0Ax^2 + Bx + C = 0.
4
Factor the quadratic equation to find the potential values of xx.
(x+7)(x3)=0(x + 7)(x - 3) = 0, so x=7x = -7 or x=3x = 3
We need two numbers that multiply to 21-21 and add to 44, which are 77 and 3-3.
5
Check the potential solutions against the domain of the original logarithmic equation.
x=3x = 3
The arguments of the logarithms, x+5x + 5 and x1x - 1, must be strictly positive. For x=7x = -7, the arguments are negative, so x=7x = -7 is an extraneous solution. For x=3x = 3, both arguments are positive, so x=3x = 3 is the only valid solution.

Anahtar Kavram

Solving logarithmic equations by applying logarithmic properties and converting to exponential form, while checking for extraneous solutions.
Soru 2252Soru

In the standard (x,y)(x, y) coordinate plane, a line segment has endpoints A(3,2)A(-3, 2) and B(1,4)B(1, 4). The segment is reflected across the line y=xy = -x to form segment ABA'B', which is then translated 55 units to the right and 33 units down to form segment ABA''B''. What are the coordinates of the midpoint of segment ABA''B''?

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Cevap: (2,2)(2, -2)

Cevap

(2,2)(2, -2)
The correct answer is (2,2)(2, -2). The midpoint of the original segment ABAB is calculated as M(1,3)M(-1, 3). Reflecting MM across the line y=xy = -x yields M(3,1)M'(-3, 1). Translating MM' by 55 units right and 33 units down results in the final midpoint M(2,2)M''(2, -2).

Adım Adım Çözüm

1
Find the coordinates of the midpoint of the original segment ABAB.
The midpoint MM of ABAB is calculated using the midpoint formula: M=(3+12,2+42)=(1,3)M = \left(\frac{-3 + 1}{2}, \frac{2 + 4}{2}\right) = (-1, 3).
Since translations, reflections, and dilations preserve midpoints, the midpoint of the final image segment ABA''B'' is the same point obtained by applying the transformations to the midpoint of the original segment ABAB.
2
Apply the reflection across the line y=xy = -x to the midpoint M(1,3)M(-1, 3).
Using the reflection rule (x,y)(y,x)(x, y) \rightarrow (-y, -x), the reflected midpoint is M=(3,1)M' = (-3, 1).
A reflection across y=xy = -x swaps the coordinates of a point and negates both values.
3
Apply the translation of 55 units right and 33 units down to the point M(3,1)M'(-3, 1).
Using the translation rule (x,y)(x+5,y3)(x, y) \rightarrow (x + 5, y - 3), the final midpoint is M=(3+5,13)=(2,2)M'' = (-3 + 5, 1 - 3) = (2, -2).
Translating a point right increases the x-coordinate, and translating it down decreases the y-coordinate.

Anahtar Kavram

Applying composite transformations (reflection across y=xy = -x followed by translation) to geometric objects and midpoints in the coordinate plane.
Tahmini Süre:2m 0s
Soru 2253Soru

In acute triangle ABCABC, the measure of A\angle A is 7474^\circ. The altitude from vertex BB to side ACAC and the altitude from vertex CC to side ABAB intersect at point HH inside the triangle. What is the measure, in degrees, of BHC\angle BHC?

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Cevap: 106

Cevap

The measure of BHC\angle BHC is 106 degrees.
In quadrilateral AEHDAEHD, the sum of the angles is 360360^\circ. Since the angles at EE and DD are 9090^\circ because they are formed by altitudes, the sum of A\angle A and EHD\angle EHD must be 180180^\circ. Thus, EHD=18074=106\angle EHD = 180^\circ - 74^\circ = 106^\circ. Since BHC\angle BHC and EHD\angle EHD are vertical angles, BHC=106\angle BHC = 106^\circ.

Adım Adım Çözüm

1
Define the intersection points of the altitudes with the opposite sides.
Let the altitude from vertex BB intersect side ACAC at point DD, and let the altitude from vertex CC intersect side ABAB at point EE. Therefore, ADH=90\angle ADH = 90^\circ and AEH=90\angle AEH = 90^\circ.
Altitudes by definition are perpendicular to the sides they intersect, forming 9090^\circ angles.
2
Analyze the sum of interior angles in the quadrilateral AEHDAEHD.
The sum of the interior angles of a quadrilateral is 360360^\circ, so A+AEH+EHD+ADH=360\angle A + \angle AEH + \angle EHD + \angle ADH = 360^\circ.
Any quadrilateral can be split into two triangles, making the sum of its interior angles 360360^\circ.
3
Substitute the known angle measures to find the measure of EHD\angle EHD.
74+90+EHD+90=360    254+EHD=360    EHD=10674^\circ + 90^\circ + \angle EHD + 90^\circ = 360^\circ \implies 254^\circ + \angle EHD = 360^\circ \implies \angle EHD = 106^\circ.
Solving the linear equation for the unknown angle EHD\angle EHD.
4
Relate EHD\angle EHD to the target angle BHC\angle BHC.
Since line segments BDBD and CECE intersect at HH, the angles BHC\angle BHC and EHD\angle EHD are vertical angles, so BHC=EHD=106\angle BHC = \angle EHD = 106^\circ.
Vertical angles are equal in measure.

Anahtar Kavram

The sum of angles in quadrilaterals, the definition of altitudes, and vertical angles within triangles.
Tahmini Süre:2m 0s
Soru 2254Soru

In the standard (x,y)(x, y) coordinate plane, the line described by the equation 2x3y=102x - 3y = 10 is translated 22 units to the left and 11 unit up. What is the yy-intercept of the translated line?

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Cevap: 1-1

Cevap

The correct answer is 1-1.
The correct answer is 1-1. Translating a line 2 units to the left shifts every point on the line by 2-2 in the xx-direction, which is represented algebraically by substituting x+2x + 2 for xx. Translating it 1 unit up shifts every point by +1+1 in the yy-direction, represented by substituting y1y - 1 for yy. Substituting these into the original equation 2x3y=102x - 3y = 10 yields 2(x+2)3(y1)=102(x + 2) - 3(y - 1) = 10. Simplifying this equation gives 2x+43y+3=102x + 4 - 3y + 3 = 10, which becomes 2x3y=32x - 3y = 3. To find the yy-intercept of this new line, we set x=0x = 0, giving 3y=3-3y = 3, which solves to y=1y = -1. Alternatively, we can find the original yy-intercept of (0,10/3)(0, -10/3). Under the translation, this point shifts to (02,10/3+1)=(2,7/3)(0 - 2, -10/3 + 1) = (-2, -7/3). Since the slope of the line remains 2/32/3, the new line equation is y(7/3)=(2/3)(x(2))y - (-7/3) = (2/3)(x - (-2)), which simplifies to y=(2/3)x1y = (2/3)x - 1, confirming the yy-intercept is 1-1.

Adım Adım Çözüm

1
Express the translation of the coordinates mathematically. Translating a line 2 units to the left replaces xx with x+2x + 2. Translating it 1 unit up replaces yy with y1y - 1.
The substitution expressions are xx+2x \to x + 2 and yy1y \to y - 1.
This sets up the algebraic transformation of the original line's equation.
2
Substitute the expressions into the original equation 2x3y=102x - 3y = 10 and simplify.
2(x+2)3(y1)=10    2x+43y+3=10    2x3y+7=10    2x3y=32(x + 2) - 3(y - 1) = 10 \implies 2x + 4 - 3y + 3 = 10 \implies 2x - 3y + 7 = 10 \implies 2x - 3y = 3.
This derives the equation of the translated line.
3
Find the yy-intercept of the translated line 2x3y=32x - 3y = 3 by setting x=0x = 0.
2(0)3y=3    3y=3    y=12(0) - 3y = 3 \implies -3y = 3 \implies y = -1.
The yy-intercept is the point on the line where x=0x = 0.

Anahtar Kavram

Translating linear equations in the standard coordinate plane
Tahmini Süre:1m 30s
Soru 2255Soru

A circle in the standard (x,y)(x,y) coordinate plane is defined by the equation 3x2+3y224x+12y+k=03x^2 + 3y^2 - 24x + 12y + k = 0, where kk is a constant. If the circle is tangent to the line y=2y = 2, what is the value of kk?

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Cevap: 12

Cevap

12
The correct answer is 12. Dividing the given equation 3x2+3y224x+12y+k=03x^2 + 3y^2 - 24x + 12y + k = 0 by 33 gives x2+y28x+4y+k3=0x^2 + y^2 - 8x + 4y + \frac{k}{3} = 0. Completing the square for both variables yields (x4)2+(y+2)2=20k3(x-4)^2 + (y+2)^2 = 20 - \frac{k}{3}. This represents a circle centered at (4,2)(4, -2) with a radius squared of r2=20k3r^2 = 20 - \frac{k}{3}. A circle centered at (4,2)(4, -2) that is tangent to the line y=2y = 2 has a radius equal to the vertical distance between y=2y = -2 and y=2y = 2, which is 22=4|-2 - 2| = 4. Thus, r2=16r^2 = 16. Setting 20k3=1620 - \frac{k}{3} = 16 yields k3=4\frac{k}{3} = 4, which gives k=12k = 12.

Adım Adım Çözüm

1
Divide the entire equation by 3 to normalize the coefficients of the quadratic terms.
x2+y28x+4y+k3=0x^2 + y^2 - 8x + 4y + \frac{k}{3} = 0
The standard equation of a circle requires the coefficients of x2x^2 and y2y^2 to be 1.
2
Complete the square for the xx and yy terms.
(x4)216+(y+2)24+k3=0(x4)2+(y+2)2=20k3(x - 4)^2 - 16 + (y + 2)^2 - 4 + \frac{k}{3} = 0 \Rightarrow (x - 4)^2 + (y + 2)^2 = 20 - \frac{k}{3}
This rewrites the equation in the standard form (xh)2+(yk)2=r2(x - h)^2 + (y - k)^2 = r^2 to identify the center and radius.
3
Identify the center of the circle and set up the radius relationship.
Center is (4,2)(4, -2) and the radius squared is r2=20k3r^2 = 20 - \frac{k}{3}.
Comparing (x4)2+(y+2)2=20k3(x - 4)^2 + (y + 2)^2 = 20 - \frac{k}{3} to the standard form gives the center (h,k)=(4,2)(h, k) = (4, -2) and r2r^2.
4
Determine the radius using the tangency condition with the line y=2y = 2.
Radius r=ycenter2=22=4r = |y_{\text{center}} - 2| = |-2 - 2| = 4
Since the circle is tangent to the horizontal line y=2y = 2, the radius is the vertical distance from the center's y-coordinate to the line.
5
Solve for the constant kk using the radius squared value.
r2=1620k3=164=k3k=12r^2 = 16 \Rightarrow 20 - \frac{k}{3} = 16 \Rightarrow 4 = \frac{k}{3} \Rightarrow k = 12
Equating the two expressions for r2r^2 allows us to solve for kk.

Anahtar Kavram

Converting the general equation of a circle to standard form by completing the square and using geometric tangency conditions to solve for unknown constants.
Tahmini Süre:2m 0s
Soru 2256Soru

In the standard (x,y)(x, y) coordinate plane, line segment CDCD has endpoints C(2,2)C(-2, 2) and D(2,8)D(-2, 8). If segment CDCD is reflected across the yy-axis to form segment CDC'D', what are the coordinates of the midpoint of segment CDC'D'?

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Cevap: (2,5)(2, 5)

Cevap

The coordinate point (2,5)(2, 5)
The correct answer is (2,5)(2, 5) because the midpoint of the original segment CDCD is located at (2,5)(-2, 5). When a point is reflected across the yy-axis, its xx-coordinate changes sign while its yy-coordinate remains the same. Therefore, the image of the midpoint is (2,5)(2, 5).

Adım Adım Çözüm

1
Find the midpoint of the original segment CDCD.
Midpoint M=(2+(2)2,2+82)=(2,5)M = \left(\frac{-2 + (-2)}{2}, \frac{2 + 8}{2}\right) = (-2, 5)
The midpoint formula is M=(x1+x22,y1+y22)M = \left(\frac{x_1 + x_2}{2}, \frac{y_1 + y_2}{2}\right).
2
Apply the reflection across the yy-axis to the midpoint.
M=((2),5)=(2,5)M' = (-(-2), 5) = (2, 5)
Reflecting a point (x,y)(x, y) across the yy-axis maps it to (x,y)(-x, y).

Anahtar Kavram

Reflection of points and segments across the axes in the coordinate plane

Alternatif Yöntem

Instead of finding the midpoint first, you can reflect the endpoints C(2,2)C(-2, 2) and D(2,8)D(-2, 8) across the yy-axis to get C(2,2)C'(2, 2) and D(2,8)D'(2, 8). Then, apply the midpoint formula to these new coordinates to get the midpoint: (2+22,2+82)=(2,5)\left(\frac{2 + 2}{2}, \frac{2 + 8}{2}\right) = (2, 5).
Tahmini Süre:45s
Soru 2257Soru

A water tank is being drained at a constant rate. After 22 hours of draining, the tank contains 140140 gallons of water, and after 55 hours, it contains 8080 gallons. When the relationship between the time spent draining, tt, and the volume of water, vv, is plotted on a standard coordinate plane with tt on the horizontal axis, what is the slope of the resulting line?

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Cevap: 20-20

Cevap

The slope of the line is 20-20.
The correct answer is 20-20. The slope represents the rate of change of the volume of water with respect to time. Using the points (2,140)(2, 140) and (5,80)(5, 80), the slope is calculated as the change in volume divided by the change in time: 8014052=603=20\frac{80 - 140}{5 - 2} = \frac{-60}{3} = -20.

Adım Adım Çözüm

1
Identify the coordinates of the two data points from the problem context.
The two points are (2,140)(2, 140) and (5,80)(5, 80), where time tt represents the horizontal coordinate and volume vv represents the vertical coordinate.
The problem defines the horizontal axis as representing time tt and the vertical axis as representing volume vv.
2
Apply the slope formula m=v2v1t2t1m = \frac{v_2 - v_1}{t_2 - t_1} using the coordinates from Step 1.
m=8014052=603=20m = \frac{80 - 140}{5 - 2} = \frac{-60}{3} = -20.
Calculating the ratio of change in the vertical axis to the change in the horizontal axis gives the slope of the line.

Anahtar Kavram

Slope as a constant rate of change in a linear relationship
Tahmini Süre:1m 0s
Soru 2258Soru

In the standard (x,y)(x, y) coordinate plane, line LL has a yy-intercept of 44. When line LL is translated horizontally to the right by 33 units, the yy-intercept of the resulting line is 66 units less than the yy-intercept of line LL. What is the xx-intercept of line LL?

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Cevap: 2-2

Cevap

The xx-intercept of line LL is 2-2.
The original line LL can be written as y=mx+4y = mx + 4. Translating the line horizontally to the right by 33 units replaces xx with x3x - 3, resulting in the equation y=m(x3)+4=mx3m+4y = m(x - 3) + 4 = mx - 3m + 4. The yy-intercept of this new line is 43m4 - 3m. We are given that this new yy-intercept is 66 units less than the original yy-intercept of 44, which gives the equation 43m=464 - 3m = 4 - 6. Solving for mm yields 3m=6    m=2-3m = -6 \implies m = 2. With a slope of 22 and a yy-intercept of 44, the equation of the original line LL is y=2x+4y = 2x + 4. To find the xx-intercept, we set y=0y = 0, which gives 2x+4=0    x=22x + 4 = 0 \implies x = -2.

Adım Adım Çözüm

1
Write the general equation of line LL in slope-intercept form.
y=mx+4y = mx + 4, where mm is the slope of line LL.
The yy-intercept of line LL is given as 44, which represents the constant term bb in y=mx+by = mx + b.
2
Apply the horizontal translation of 33 units to the right.
y=m(x3)+4y = m(x - 3) + 4, which simplifies to y=mx3m+4y = mx - 3m + 4.
Translating a function horizontally to the right by hh units replaces xx with xhx - h.
3
Determine the slope mm using the change in yy-intercept.
The new yy-intercept is 43m4 - 3m. Since this is 66 units less than the original yy-intercept of 44, we set up the equation 43m=46    3m=6    m=24 - 3m = 4 - 6 \implies -3m = -6 \implies m = 2.
We relate the algebraic expression for the new yy-intercept to the given numerical relationship.
4
Find the xx-intercept of line LL by setting y=0y = 0.
2x+4=0    2x=4    x=22x + 4 = 0 \implies 2x = -4 \implies x = -2.
The xx-intercept is the value of xx when the line crosses the xx-axis, meaning y=0y = 0.

Anahtar Kavram

Linear Equations and Graphing
Soru 2259Soru

A circle in the first quadrant of the standard (x,y)(x,y) coordinate plane is tangent to the xx-axis and is also tangent to the line y=43xy = \frac{4}{3}x. If the center of the circle lies on the line with equation y=3x10y = 3x - 10, what is the radius of the circle?

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Cevap: 2

Cevap

The radius of the circle is 2.
The correct answer is obtained by determining that the center of a circle tangent to the xx-axis in the first quadrant has the form (h,R)(h, R) where RR is the radius. Using the distance from this point to the line 4x3y=04x - 3y = 0 gives h=2Rh = 2R to ensure the center remains in the first quadrant. Substituting (2R,R)(2R, R) into the line y=3x10y = 3x - 10 yields R=3(2R)10R = 3(2R) - 10, which solves to R=2R = 2.

Adım Adım Çözüm

1
Determine the relation between the circle's center coordinates and its radius.
The center is (h,R)(h, R) where RR is the radius.
Because the circle is tangent to the xx-axis and lies in the first quadrant, the y-coordinate of its center must equal its radius.
2
Apply the point-to-line distance formula from the center to the line y=43xy = \frac{4}{3}x.
The relation is 4h3R=5R|4h - 3R| = 5R.
The distance from the center (h,R)(h, R) to the line 4x3y=04x - 3y = 0 must equal the radius RR.
3
Solve the absolute value equation for hh in terms of RR.
Since h>0h > 0, we find h=2Rh = 2R.
The positive case 4h3R=5R4h - 3R = 5R gives h=2Rh = 2R, whereas the negative case 4h3R=5R4h - 3R = -5R gives a negative hh which violates the first-quadrant condition.
4
Substitute the center coordinates (2R,R)(2R, R) into the line y=3x10y = 3x - 10 and solve for RR.
R=2R = 2.
The center lies on this line, so its coordinates must satisfy the line's equation.

Anahtar Kavram

Equations and Graphs of Circles
Soru 2260Soru

A circle in the standard (x,y)(x, y) coordinate plane is defined by the equation (x1)2+(y2)2=10(x - 1)^2 + (y - 2)^2 = 10, and a line is defined by the equation y=3x1y = 3x - 1. The line intersects the circle at two points, (x1,y1)(x_1, y_1) and (x2,y2)(x_2, y_2). What is the sum of the yy-coordinates of these two points of intersection?

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Cevap: 4

Cevap

The sum of the yy-coordinates of the intersection points is 4.
Substituting y=3x1y = 3x - 1 into the circle's equation gives (x1)2+(3x3)2=10(x-1)^2 + (3x-3)^2 = 10. Factoring out 3 from the second term yields (x1)2+9(x1)2=10(x-1)^2 + 9(x-1)^2 = 10, which simplifies to 10(x1)2=1010(x-1)^2 = 10, or (x1)2=1(x-1)^2 = 1. Solving for xx gives x=0x = 0 and x=2x = 2. Substituting these values into the linear equation gives the corresponding yy-coordinates: y=1y = -1 when x=0x = 0, and y=5y = 5 when x=2x = 2. The sum of these yy-coordinates is 5+(1)=45 + (-1) = 4.

Adım Adım Çözüm

1
Substitute the expression for yy from the linear equation into the circle's equation.
(x1)2+(3x3)2=10(x-1)^2 + (3x-3)^2 = 10
To reduce the system of two equations to a single equation in terms of xx.
2
Factor out 3 from the term (3x3)(3x-3) and simplify the equation.
10(x1)2=1010(x-1)^2 = 10, which simplifies to (x1)2=1(x-1)^2 = 1
To solve for the xx-coordinates of the intersection points.
3
Solve the simplified quadratic equation for xx.
x1=2x_1 = 2 and x2=0x_2 = 0
To find the xx-coordinates of the two intersection points.
4
Substitute the xx-values back into the linear equation y=3x1y = 3x - 1 to find the corresponding yy-coordinates.
y1=3(2)1=5y_1 = 3(2) - 1 = 5 and y2=3(0)1=1y_2 = 3(0) - 1 = -1
To determine the yy-coordinates of the intersection points (2,5)(2, 5) and (0,1)(0, -1).
5
Add the two yy-coordinates together.
5+(1)=45 + (-1) = 4
To find the sum of the yy-coordinates as requested by the question.

Anahtar Kavram

Solving systems of linear and circular equations by substitution

Alternatif Yöntem

Instead of finding the individual coordinates, substitute y1=3x11y_1 = 3x_1 - 1 and y2=3x21y_2 = 3x_2 - 1 to write the sum as y1+y2=3(x1+x2)2y_1 + y_2 = 3(x_1 + x_2) - 2. Expanding the substitution equation gives 10x220x=010x^2 - 20x = 0. By Vieta's formulas, the sum of the roots x1+x2=(20)/10=2x_1 + x_2 = -(-20)/10 = 2. Substituting this back gives y1+y2=3(2)2=4y_1 + y_2 = 3(2) - 2 = 4.
Tahmini Süre:1m 30s
ÖncekiSayfa 113 / 278Sonraki
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