Coordinate Geometry

273 soru

Soru 61Soru

A system administrator monitors the temperatures of two servers, Server A and Server B, over a period of tt hours after midnight. The temperature of Server A, in degrees Celsius, is modeled by a linear function of time. At t=2t = 2 hours, the temperature is 30C30^\circ\text{C}, and at t=at = a hours (where a>2a > 2), the temperature is (30+a22a)C(30 + a^2 - 2a)^\circ\text{C}. The temperature of Server B, in degrees Celsius, is also modeled by a linear function of time. At t=1t = 1 hour, Server B's temperature is 25C25^\circ\text{C}, and at t=at = a hours, its temperature is (a2+30)C(a^2 + 30)^\circ\text{C}. If the temperature of Server B increases at a constant rate that is 1.51.5 times the constant rate of temperature increase of Server A, what is the value of aa?

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Cevap: 5

Cevap

The value of aa is 5.
To find the rate of change (slope) for each server, we apply the slope formula m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1}. For Server A, the slope is mA=(30+a22a)30a2=am_A = \frac{(30 + a^2 - 2a) - 30}{a - 2} = a. For Server B, the slope is mB=(a2+30)25a1=a2+5a1m_B = \frac{(a^2 + 30) - 25}{a - 1} = \frac{a^2 + 5}{a - 1}. We are given that mB=1.5mAm_B = 1.5 m_A, which yields the equation a2+5a1=1.5a\frac{a^2 + 5}{a - 1} = 1.5a. Multiplying both sides by a1a - 1 gives a2+5=1.5a(a1)=1.5a21.5aa^2 + 5 = 1.5a(a - 1) = 1.5a^2 - 1.5a. Grouping all terms on one side gives 0.5a21.5a5=00.5a^2 - 1.5a - 5 = 0. Multiplying the equation by 2 results in a23a10=0a^2 - 3a - 10 = 0, which factors as (a5)(a+2)=0(a - 5)(a + 2) = 0. Since a>2a > 2, the only valid solution is the positive root, which is 5.

Adım Adım Çözüm

1
Calculate the constant rate of temperature increase (slope) for Server A, mAm_A, using the coordinates (2,30)(2, 30) and (a,30+a22a)(a, 30 + a^2 - 2a).
mA=(30+a22a)30a2=a22aa2=a(a2)a2=am_A = \frac{(30 + a^2 - 2a) - 30}{a - 2} = \frac{a^2 - 2a}{a - 2} = \frac{a(a-2)}{a-2} = a (since a>2a > 2)
The constant rate of change of a linear temperature model is represented by the slope of the line passing through its data points.
2
Calculate the constant rate of temperature increase (slope) for Server B, mBm_B, using the coordinates (1,25)(1, 25) and (a,a2+30)(a, a^2 + 30).
mB=(a2+30)25a1=a2+5a1m_B = \frac{(a^2 + 30) - 25}{a - 1} = \frac{a^2 + 5}{a - 1}
The constant rate of change of Server B is represented by the slope of the line passing through its data points.
3
Set up the equation using the given relationship that Server B's rate of increase is 1.51.5 times Server A's rate (mB=1.5mAm_B = 1.5 m_A).
1.5a=a2+5a11.5a = \frac{a^2 + 5}{a - 1}
Equating the rate of change of Server B to 1.5 times the rate of change of Server A allows us to write an equation in terms of the variable aa.
4
Solve the equation for aa by cross-multiplying and simplifying the resulting quadratic equation.
1.5a(a1)=a2+5    1.5a21.5a=a2+5    0.5a21.5a5=0    a23a10=0    (a5)(a+2)=01.5a(a - 1) = a^2 + 5 \implies 1.5a^2 - 1.5a = a^2 + 5 \implies 0.5a^2 - 1.5a - 5 = 0 \implies a^2 - 3a - 10 = 0 \implies (a-5)(a+2) = 0
Cross-multiplying eliminates the fraction, and grouping all terms on one side forms a standard quadratic equation that can be factored.
5
Identify the valid value of aa that satisfies the initial domain constraint.
a=5a = 5 (since a=2a = -2 is rejected because the problem states a>2a > 2)
The solution must satisfy the given condition that a>2a > 2 for the time intervals to be valid.

Anahtar Kavram

Calculating and equating rates of change (slopes) of linear functions using the slope formula m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1} and solving the resulting quadratic equation.
Soru 62Soru

On a coordinate map, two tracking stations are located at the points (2,3)(2, -3) and (6,12)(-6, 12). What is the straight-line distance, in map units, between the two stations?

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Cevap: 17

Cevap

The straight-line distance between the two stations is 17 map units.
Applying the coordinate distance formula to the coordinates (2,3)(2, -3) and (6,12)(-6, 12) yields a distance of (62)2+(12(3))2=(8)2+152=64+225=289=17\sqrt{(-6 - 2)^2 + (12 - (-3))^2} = \sqrt{(-8)^2 + 15^2} = \sqrt{64 + 225} = \sqrt{289} = 17.

Adım Adım Çözüm

1
Identify coordinates of the two stations.
(x1,y1)=(2,3)(x_1, y_1) = (2, -3) and (x2,y2)=(6,12)(x_2, y_2) = (-6, 12)
Defining the coordinate variables is necessary to apply the formula correctly.
2
Apply the distance formula.
d=(62)2+(12(3))2d = \sqrt{(-6 - 2)^2 + (12 - (-3))^2}
The distance formula calculates the straight-line distance between two coordinates.
3
Simplify the arithmetic terms.
d=(8)2+152=64+225=289d = \sqrt{(-8)^2 + 15^2} = \sqrt{64 + 225} = \sqrt{289}
Simplify the differences and squares under the radical.
4
Calculate the final square root.
d=17d = 17
The square root of 289 is 17.

Anahtar Kavram

Distance Formula
Soru 63Soru

A circle is graphed in the standard (x,y)(x, y) coordinate plane such that it is tangent to the xx-axis at (4,0)(4, 0) and tangent to the yy-axis at (0,4)(0, 4). A line segment has one of its endpoints at the center of this circle and its midpoint at the point (1,1)(1, -1). What is the total length of this line segment?

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Cevap: 2342\sqrt{34}

Cevap

The total length of the line segment is 2342\sqrt{34}.
The center of the circle is determined to be C(4,4)C(4, 4) based on the points of tangency at (4,0)(4, 0) and (0,4)(0, 4). The distance between the center C(4,4)C(4, 4) and the midpoint M(1,1)M(1, -1) is calculated using the distance formula to be 34\sqrt{34}. Since the midpoint divides the segment into two equal halves, the total length of the segment is twice this distance, which is 2342\sqrt{34}.

Adım Adım Çözüm

1
Determine the coordinates of the center of the circle.
The center of the circle is C(4,4)C(4, 4).
Since the circle is tangent to the xx-axis at (4,0)(4, 0), its center must lie on the vertical line x=4x = 4. Since it is tangent to the yy-axis at (0,4)(0, 4), its center must lie on the horizontal line y=4y = 4. Their intersection gives the center of the circle at C(4,4)C(4, 4).
2
Calculate the distance from the center of the circle to the midpoint of the segment.
The distance is 34\sqrt{34}.
Using the distance formula between the center C(4,4)C(4, 4) and the midpoint M(1,1)M(1, -1): d(C,M)=(14)2+(14)2=(3)2+(5)2=9+25=34d(C, M) = \sqrt{(1 - 4)^2 + (-1 - 4)^2} = \sqrt{(-3)^2 + (-5)^2} = \sqrt{9 + 25} = \sqrt{34}.
3
Find the total length of the line segment.
The total length is 2342\sqrt{34}.
Since the midpoint divides the segment into two equal parts, the total length is twice the distance from one endpoint to the midpoint: Length=2×d(C,M)=234\text{Length} = 2 \times d(C, M) = 2\sqrt{34}.

Anahtar Kavram

Using circle tangencies to find the center, and applying the distance and midpoint formulas to determine segment properties.
Tahmini Süre:1m 30s
Soru 64Soru

In the standard (x,y)(x, y) coordinate plane, if the slope of a line passing through the points (k,k2)(k, k^2) and (k+1,(k+1)2)(k+1, (k+1)^2) is an integer, then kk must be an integer. Is this statement true or false?

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Cevap: False

Cevap

False
The statement is false because the simplified slope of the line is 2k+12k + 1. The slope 2k+12k + 1 is an integer for any half-integer value of kk (such as k=0.5k = 0.5, which yields a slope of 22), showing that kk does not have to be an integer.

Adım Adım Çözüm

1
Use the slope formula m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1} with the given coordinates (k,k2)(k, k^2) and (k+1,(k+1)2)(k+1, (k+1)^2).
The slope is m=(k+1)2k2(k+1)km = \frac{(k+1)^2 - k^2}{(k+1) - k}.
To express the slope of the line in terms of the variable kk.
2
Simplify the numerator and denominator of the slope expression.
m=k2+2k+1k21=2k+1m = \frac{k^2 + 2k + 1 - k^2}{1} = 2k + 1.
To obtain a simplified algebraic expression for the slope.
3
Set the slope equal to an arbitrary integer nn and solve for kk.
2k+1=n    k=n122k + 1 = n \implies k = \frac{n-1}{2}.
To find the set of values for kk that yield an integer slope.
4
Evaluate if kk must be an integer by choosing an integer value for nn.
If n=2n = 2, then k=212=0.5k = \frac{2-1}{2} = 0.5, which is not an integer.
To test the truth value of the statement by finding a counterexample.

Anahtar Kavram

Determining the slope of a line from two coordinate points and analyzing the algebraic properties of the slope expression.
Soru 65Soru

A hyperbola is defined by the equation 9x24y236x8y4=09x^2 - 4y^2 - 36x - 8y - 4 = 0 in the standard (x,y)(x, y) coordinate plane. What is the slope of the asymptote of this hyperbola that has a positive slope?

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Cevap: 1.5

Cevap

The positive slope of the asymptotes is 1.5.
By converting the general form of the hyperbola equation into standard form, we determine that it is a horizontal hyperbola with a=2a = 2 and b=3b = 3. The slopes of the asymptotes for a horizontal hyperbola are ±ba\pm \frac{b}{a}, making the positive slope equal to 32=1.5\frac{3}{2} = 1.5.

Adım Adım Çözüm

1
Group x-terms and y-terms, and move the constant to the other side.
9(x24x)4(y2+2y)=49(x^2 - 4x) - 4(y^2 + 2y) = 4
This prepares the equation for completing the square.
2
Complete the square for the quadratic expressions in x and y.
9(x2)24(y+1)2=369(x - 2)^2 - 4(y + 1)^2 = 36
Completing the square yields 9[(x2)24]4[(y+1)21]=4    9(x2)2364(y+1)2+4=49[(x-2)^2 - 4] - 4[(y+1)^2 - 1] = 4 \implies 9(x-2)^2 - 36 - 4(y+1)^2 + 4 = 4.
3
Divide both sides by 36 to format the equation in standard hyperbola form.
(x2)24(y+1)29=1\frac{(x-2)^2}{4} - \frac{(y+1)^2}{9} = 1
The standard form of a horizontal hyperbola centered at (h,k)(h, k) is (xh)2a2(yk)2b2=1\frac{(x-h)^2}{a^2} - \frac{(y-k)^2}{b^2} = 1.
4
Identify the values of a and b from the denominators.
a=2a = 2 and b=3b = 3
Since a2=4a^2 = 4 and b2=9b^2 = 9, taking the square roots gives a=2a = 2 and b=3b = 3.
5
Determine the positive slope of the asymptotes using the formula for a horizontal hyperbola.
m=ba=1.5m = \frac{b}{a} = 1.5
The asymptotes for a horizontal hyperbola are given by yk=±ba(xh)y - k = \pm \frac{b}{a}(x - h), so the positive slope is ba=32=1.5\frac{b}{a} = \frac{3}{2} = 1.5.

Anahtar Kavram

Rewriting a hyperbola equation from general form to standard form to find asymptote equations.
Tahmini Süre:1m 30s
Soru 66Soru

In the standard (x,y)(x, y) coordinate plane, a line segment ABAB has endpoints A(2,5)A(2, 5) and B(6,1)B(6, -1). Segment ABAB is reflected across the line y=xy = -x to form segment ABA'B'. Then, segment ABA'B' is dilated by a scale factor of 33 with a center of dilation at C(2,1)C(2, -1) to form segment ABA''B''. What is the sum of the xx- and yy-coordinates of the midpoint of segment ABA''B''?

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Cevap: -20

Cevap

-20
To find the coordinates of the midpoint of the transformed segment ABA''B'', we can track the midpoint of the original segment ABAB through each transformation. The midpoint of ABAB is M(4,2)M(4, 2). Reflecting MM across the line y=xy = -x swaps and negates its coordinates, resulting in M(2,4)M'(-2, -4). Dilating MM' by a scale factor of 33 centered at C(2,1)C(2, -1) means finding the point MM'' such that the vector CM\vec{CM''} is 33 times the vector CM\vec{CM'}. This is computed as M=(2+3(22),1+3(4(1)))=(10,10)M'' = (2 + 3(-2 - 2), -1 + 3(-4 - (-1))) = (-10, -10). The sum of these coordinates is 10+(10)=20-10 + (-10) = -20.

Adım Adım Çözüm

1
Find the midpoint of the original segment ABAB.
The midpoint MM of segment ABAB is M=(2+62,5+(1)2)=(4,2)M = \left(\frac{2 + 6}{2}, \frac{5 + (-1)}{2}\right) = (4, 2).
Since rigid transformations (reflections) and similarity transformations (dilations) preserve midpoints, we can find the final midpoint by applying the sequence of transformations directly to the initial midpoint.
2
Reflect the midpoint M(4,2)M(4, 2) across the line y=xy = -x to find the midpoint MM' of segment ABA'B'.
Applying the reflection rule (x,y)(y,x)(x, y) \rightarrow (-y, -x) to M(4,2)M(4, 2) yields M(2,4)M'(-2, -4).
Reflecting a point across the line y=xy = -x swaps its coordinates and negates both values.
3
Dilate the midpoint M(2,4)M'(-2, -4) by a scale factor of 33 with the center of dilation at C(2,1)C(2, -1) to find the midpoint MM'' of segment ABA''B''.
Using the dilation formula (x,y)=(xc+k(xxc),yc+k(yyc))(x'', y'') = (x_c + k(x' - x_c), y_c + k(y' - y_c)) with C(2,1)C(2, -1) and k=3k = 3: x=2+3(22)=10x'' = 2 + 3(-2 - 2) = -10, and y=1+3(4(1))=10y'' = -1 + 3(-4 - (-1)) = -10. This gives the midpoint M(10,10)M''(-10, -10).
A dilation centered at (xc,yc)(x_c, y_c) scales the horizontal and vertical distances from the center to the point by the scale factor kk.
4
Calculate the sum of the xx- and yy-coordinates of MM.
The sum of the coordinates is 10+(10)=20-10 + (-10) = -20.
The question asks for the sum of the coordinates of the final midpoint.

Anahtar Kavram

Applying composite transformations in the coordinate plane to geometric figures and midpoints.
Soru 67Soru

In the standard (x,y)(x, y) coordinate plane, line segment ABAB has endpoints A(2,4)A(-2, 4) and B(4,2)B(4, 2). The segment is rotated 9090^\circ counterclockwise about the origin, then reflected across the line y=xy = -x, and finally translated 33 units to the right and 22 units down. What are the coordinates of the midpoint of the final image of the segment?

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Cevap: (2,1)(2, 1)

Cevap

(2,1)(2, 1)
The correct midpoint is (2,1)(2, 1). First, the midpoint of the original segment ABAB is calculated using the midpoint formula, yielding (1,3)(1, 3). Rotating this point 9090^\circ counterclockwise about the origin maps (x,y)(x, y) to (y,x)(-y, x), which gives (3,1)(-3, 1). Reflecting (3,1)(-3, 1) across the line y=xy = -x maps (x,y)(x, y) to (y,x)(-y, -x), resulting in (1,3)(-1, 3). Finally, translating this point 33 units to the right and 22 units down yields (1+3,32)=(2,1)(-1 + 3, 3 - 2) = (2, 1).

Adım Adım Çözüm

1
Find the midpoint of the original line segment ABAB.
M(1,3)M(1, 3)
The midpoint formula is M=(x1+x22,y1+y22)M = \left(\frac{x_1 + x_2}{2}, \frac{y_1 + y_2}{2}\right). Substituting the coordinates of A(2,4)A(-2, 4) and B(4,2)B(4, 2) yields (2+42,4+22)=(1,3)\left(\frac{-2 + 4}{2}, \frac{4 + 2}{2}\right) = (1, 3).
2
Apply a 9090^\circ counterclockwise rotation about the origin to the midpoint.
M(3,1)M'(-3, 1)
A 9090^\circ counterclockwise rotation about the origin maps (x,y)(y,x)(x, y) \rightarrow (-y, x). Applying this rule to M(1,3)M(1, 3) gives (3,1)(-3, 1).
3
Reflect the rotated point across the line y=xy = -x.
M(1,3)M''(-1, 3)
A reflection across the line y=xy = -x maps (x,y)(y,x)(x, y) \rightarrow (-y, -x). Applying this rule to M(3,1)M'(-3, 1) gives (1,3)(-1, 3).
4
Translate the reflected point 33 units right and 22 units down.
M(2,1)M'''(2, 1)
A translation of 33 units right and 22 units down maps (x,y)(x+3,y2)(x, y) \rightarrow (x + 3, y - 2). Translating M(1,3)M''(-1, 3) yields (1+3,32)=(2,1)(-1 + 3, 3 - 2) = (2, 1).

Anahtar Kavram

Composite transformations of geometric figures in the coordinate plane

Alternatif Yöntem

Instead of transforming the midpoint, you can transform the individual endpoints A(2,4)A(-2, 4) and B(4,2)B(4, 2) through all three steps. Point A(2,4)A(-2, 4) becomes A(4,2)A(2,4)A(5,2)A'(-4, -2) \rightarrow A''(2, 4) \rightarrow A'''(5, 2). Point B(4,2)B(4, 2) becomes B(2,4)B(4,2)B(1,0)B'(-2, 4) \rightarrow B''(-4, 2) \rightarrow B'''(-1, 0). The midpoint of AA''' and BB''' is then calculated to be (5+(1)2,2+02)=(2,1)\left(\frac{5 + (-1)}{2}, \frac{2 + 0}{2}\right) = (2, 1).
Tahmini Süre:1m 30s
Soru 68Soru

In the standard (x,y)(x,y) coordinate plane, line qq is perpendicular to the line with equation y=34x2y = \frac{3}{4}x - 2. If line qq passes through the point (2,1)(2, 1), what is the yy-intercept of line qq?

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Cevap: 113\frac{11}{3}

Cevap

The yy-intercept of line qq is 113\frac{11}{3}.
The slope of the given line y=34x2y = \frac{3}{4}x - 2 is 34\frac{3}{4}. The slope of a perpendicular line is the negative reciprocal of the original slope, which is 43-\frac{4}{3}. Using the point-slope form of a linear equation with the point (2,1)(2, 1) gives y1=43(x2)y - 1 = -\frac{4}{3}(x - 2). To find the yy-intercept, set x=0x = 0, which gives y1=43(2)=83y - 1 = -\frac{4}{3}(-2) = \frac{8}{3}. Adding 11 to both sides yields y=83+1=113y = \frac{8}{3} + 1 = \frac{11}{3}. Therefore, the correct yy-intercept is 113\frac{11}{3}.

Adım Adım Çözüm

1
Determine the slope of the perpendicular line qq.
The slope of the given line is 34\frac{3}{4}, so the slope of line qq (the negative reciprocal) is 43-\frac{4}{3}.
Perpendicular lines have slopes that are negative reciprocals of each other.
2
Write the equation of line qq using the point-slope form with the point (2,1)(2, 1).
y1=43(x2)y - 1 = -\frac{4}{3}(x - 2)
The point-slope form yy1=m(xx1)y - y_1 = m(x - x_1) is used to find the equation of a line given its slope and a point on the line.
3
Find the yy-intercept by setting x=0x = 0 and solving for yy.
y1=43(02)y1=83y=83+1=113y - 1 = -\frac{4}{3}(0 - 2) \Rightarrow y - 1 = \frac{8}{3} \Rightarrow y = \frac{8}{3} + 1 = \frac{11}{3}
The yy-intercept of a line is the value of yy when x=0x = 0.

Anahtar Kavram

The slope of a line perpendicular to a line with slope mm is 1m-\frac{1}{m}. The equation of a line can be written in point-slope form as yy1=m(xx1)y - y_1 = m(x - x_1).
Soru 69Soru

A toy car moves along a straight track. Its position in meters, ss, is plotted against time in seconds, tt, on a standard coordinate plane. At t=2t = 2 seconds, the car is at a position of 3-3 meters. From t=2t = 2 to t=6t = 6 seconds, the position changes at a constant rate of mm meters per second. From t=6t = 6 to t=8t = 8 seconds, the position changes at a constant rate of 2m+32m + 3 meters per second. If the average rate of change of the car's position over the entire interval from t=2t = 2 to t=8t = 8 seconds is 53\frac{5}{3} meters per second, what is the constant rate of change, in meters per second, from t=6t = 6 to t=8t = 8 seconds?

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Cevap: 4

Cevap

The correct constant rate of change from t=6t = 6 to t=8t = 8 seconds is 44 meters per second.
The correct answer of 44 meters per second is found by setting up the displacement for each interval in terms of mm. The displacement during the first interval is 4m4m, and the displacement during the second interval is 2(2m+3)=4m+62(2m + 3) = 4m + 6. Adding these gives a total displacement of 8m+68m + 6 over a total time of 66 seconds. Dividing total displacement by total time yields the average rate of change, 8m+66=4m+33\frac{8m + 6}{6} = \frac{4m + 3}{3}. Setting this equal to the given average rate of 53\frac{5}{3} yields m=12m = \frac{1}{2}. Finally, substituting this back into the rate expression for the second interval, 2m+32m + 3, gives 2(1/2)+3=42(1/2) + 3 = 4.

Adım Adım Çözüm

1
Express the displacement in each time interval using the rate of change (slope) formula: Δs=slope×Δt\Delta s = \text{slope} \times \Delta t.
For t=2t = 2 to t=6t = 6: Δs1=m×(62)=4m\Delta s_1 = m \times (6 - 2) = 4m. For t=6t = 6 to t=8t = 8: Δs2=(2m+3)×(86)=2(2m+3)=4m+6\Delta s_2 = (2m + 3) \times (8 - 6) = 2(2m + 3) = 4m + 6.
The constant rate of change in a position-time graph is the slope of the line, which relates time intervals to position displacements.
2
Calculate the total displacement over the entire interval from t=2t = 2 to t=8t = 8 seconds.
Total displacement Δstotal=Δs1+Δs2=4m+(4m+6)=8m+6\Delta s_{\text{total}} = \Delta s_1 + \Delta s_2 = 4m + (4m + 6) = 8m + 6.
The total displacement is the sum of the individual displacements over consecutive sub-intervals.
3
Set up the average rate of change equation using the total displacement and the total time elapsed (Δttotal=82=6\Delta t_{\text{total}} = 8 - 2 = 6 seconds).
Average rate of change = 8m+66=4m+33\frac{8m + 6}{6} = \frac{4m + 3}{3}.
The average rate of change is the net displacement divided by the total time elapsed.
4
Equate the expression for the average rate of change to the given value of 53\frac{5}{3} and solve for mm.
4m+33=534m+3=54m=2m=12\frac{4m + 3}{3} = \frac{5}{3} \Rightarrow 4m + 3 = 5 \Rightarrow 4m = 2 \Rightarrow m = \frac{1}{2}.
Solving this linear equation yields the value of the parameter mm that satisfies the average rate condition.
5
Calculate the rate of change for the second interval from t=6t = 6 to t=8t = 8 seconds by substituting m=12m = \frac{1}{2} into 2m+32m + 3.
Rate of change = 2(12)+3=1+3=42\left(\frac{1}{2}\right) + 3 = 1 + 3 = 4.
The question asks for the rate of change during the second interval, which is defined in terms of mm as 2m+32m + 3.

Anahtar Kavram

Slope as a constant rate of change in a piecewise linear model
Tahmini Süre:3m 0s
Soru 70Soru

In the standard (x,y)(x, y) coordinate plane, a line L1L_1 passes through the points (2,5)(2, 5) and (1,4)(-1, -4). A second line, L2L_2, passes through the yy-intercept of L1L_1 and has a slope that is twice the slope of L1L_1. What is the xx-intercept of L2L_2?

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Cevap: 16\frac{1}{6}

Cevap

The xx-intercept of L2L_2 is 16\frac{1}{6}.
To find the xx-intercept of L2L_2, the slope and yy-intercept of L1L_1 must first be found. The slope of L1L_1 is 5(4)2(1)=3\frac{5 - (-4)}{2 - (-1)} = 3. Using the point-slope form with the point (2,5)(2, 5), the equation of L1L_1 is y5=3(x2)    y=3x1y - 5 = 3(x - 2) \implies y = 3x - 1, meaning its yy-intercept is (0,1)(0, -1). The second line, L2L_2, has a slope of 2×3=62 \times 3 = 6 and passes through the same yy-intercept (0,1)(0, -1), giving the equation y=6x1y = 6x - 1. Setting y=0y = 0 to find the xx-intercept yields 6x1=0    x=166x - 1 = 0 \implies x = \frac{1}{6}.

Adım Adım Çözüm

1
Calculate the slope of line L1L_1 using the coordinates (2,5)(2, 5) and (1,4)(-1, -4).
The slope of L1L_1 is m1=5(4)2(1)=93=3m_1 = \frac{5 - (-4)}{2 - (-1)} = \frac{9}{3} = 3.
The slope of a line containing (x1,y1)(x_1, y_1) and (x2,y2)(x_2, y_2) is defined as y2y1x2x1\frac{y_2 - y_1}{x_2 - x_1}.
2
Determine the equation and the yy-intercept of line L1L_1.
The equation of L1L_1 in point-slope form is y5=3(x2)    y=3x1y - 5 = 3(x - 2) \implies y = 3x - 1. The yy-intercept of L1L_1 is (0,1)(0, -1).
Writing the equation in slope-intercept form y=mx+by = mx + b directly identifies the yy-intercept at (0,b)(0, b).
3
Determine the equation of line L2L_2.
The slope of L2L_2 is 2×3=62 \times 3 = 6. Since L2L_2 passes through the yy-intercept of L1L_1 at (0,1)(0, -1), its equation is y=6x1y = 6x - 1.
Using the relationship for the doubled slope and the shared yy-intercept, the slope-intercept form of the second line is determined.
4
Find the xx-intercept of L2L_2 by setting y=0y = 0.
Setting y=0y = 0 in the equation y=6x1y = 6x - 1 gives 0=6x1    6x=1    x=160 = 6x - 1 \implies 6x = 1 \implies x = \frac{1}{6}.
The xx-intercept occurs where the line crosses the xx-axis, which corresponds to setting y=0y = 0.

Anahtar Kavram

Determining linear equations from coordinates, finding slopes, and calculating coordinate intercepts.
Soru 71Soru

A line segment in the standard (x,y)(x, y) coordinate plane has endpoints at (1,a)(1, a) and (5,a2)(5, a^2). The perpendicular bisector of this segment is parallel to the line defined by the equation x+3y=6x + 3y = 6. What is the sum of all possible values of the constant aa?

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Cevap: 1

Cevap

The sum of all possible values of the constant aa is 1.
To find the sum of all possible values of the constant aa, we first find the slope of the line x+3y=6x + 3y = 6 by writing it in slope-intercept form: y=13x+2y = -\frac{1}{3}x + 2. Since the perpendicular bisector is parallel to this line, its slope is also 13-\frac{1}{3}. The line segment is perpendicular to its perpendicular bisector, so the slope of the line segment is the negative reciprocal of 13-\frac{1}{3}, which is 33. Setting the slope of the segment a2a51\frac{a^2 - a}{5 - 1} equal to 33 gives the equation a2a4=3\frac{a^2 - a}{4} = 3, which simplifies to a2a12=0a^2 - a - 12 = 0. Solving this quadratic equation yields (a4)(a+3)=0(a - 4)(a + 3) = 0, giving the values a=4a = 4 and a=3a = -3. The sum of these possible values is 4+(3)=14 + (-3) = 1.

Adım Adım Çözüm

1
Find the slope of the given line x+3y=6x + 3y = 6.
The slope is 13-\frac{1}{3}.
Rewriting the equation in slope-intercept form (y=mx+by = mx + b) gives y=13x+2y = -\frac{1}{3}x + 2, showing the slope is 13-\frac{1}{3}.
2
Determine the slope of the line segment.
The slope is 3.
The line segment is perpendicular to its perpendicular bisector. Because the perpendicular bisector is parallel to the reference line, its slope is also 13-\frac{1}{3}. The line segment's slope is the negative reciprocal of 13-\frac{1}{3}, which is 33.
3
Write the slope of the segment in terms of aa and set it equal to 3.
a2a4=3\frac{a^2 - a}{4} = 3
Using the slope formula with endpoints (1,a)(1, a) and (5,a2)(5, a^2) gives the expression a2a51\frac{a^2 - a}{5 - 1}.
4
Solve the quadratic equation for aa.
a=4a = 4 or a=3a = -3
Multiplying both sides by 4 yields a2a=12a^2 - a = 12, which simplifies to the quadratic a2a12=0a^2 - a - 12 = 0. Factoring gives (a4)(a+3)=0(a - 4)(a + 3) = 0.
5
Sum all possible values of aa.
1
The sum of the values is 4+(3)=14 + (-3) = 1.

Anahtar Kavram

Understanding that parallel lines have equal slopes, perpendicular lines have slopes that are negative reciprocals of each other, and applying the slope formula to solve for coordinate variables.
Soru 72Soru

In the standard (x,y)(x, y) coordinate plane, the triangular region RR is bounded by the lines y=2xy = 2x, y=x+9y = -x + 9, and the xx-axis. A vertical line x=kx = k (where 0<k<90 < k < 9) divides region RR into two sub-regions. If the area of the sub-region to the right of the line x=kx = k is exactly 88, what is the value of kk?

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Cevap: 5

Cevap

5
The boundary lines intersect to form a triangle with vertices at (0,0)(0, 0), (9,0)(9, 0), and (3,6)(3, 6). Since the area to the right of x=kx = k is 88, and the total area of the triangle is 2727, kk must be greater than 33. The region to the right of x=kx = k is a right triangle with a base of 9k9 - k and a height of 9k9 - k. Setting its area 12(9k)2\frac{1}{2}(9 - k)^2 equal to 88 yields (9k)2=16(9 - k)^2 = 16, which gives 9k=49 - k = 4 (since k<9k < 9), and thus k=5k = 5.

Adım Adım Çözüm

1
Find the vertices of the triangular region RR by finding the intersection points of the boundary lines y=2xy = 2x, y=x+9y = -x + 9, and y=0y = 0.
The vertices of the triangle are A(0,0)A(0, 0), B(9,0)B(9, 0), and C(3,6)C(3, 6).
This establishes the boundaries and shape of the triangular region.
2
Determine which side of the peak x=3x = 3 the vertical line x=kx = k must lie. Calculate the total area and the area of the left portion.
The total area of the triangle is 2727. The area to the left of the peak x=3x = 3 is 99. Since the area of the region to the right of x=kx = k is 88, which is less than 1818, kk must be greater than or equal to 33.
This determines the geometric shape of the sub-region to the right of x=kx = k as a right triangle.
3
Set up the area formula for the right-hand triangle with vertices (k,0)(k, 0), (9,0)(9, 0), and (k,k+9)(k, -k + 9), and set it equal to 88.
The area is 12(9k)2=8\frac{1}{2}(9 - k)^2 = 8, which simplifies to (9k)2=16(9 - k)^2 = 16.
This relates the given area to the unknown coordinate kk.
4
Solve the equation (9k)2=16(9 - k)^2 = 16 for kk, keeping in mind that k<9k < 9.
Taking the square root gives 9k=4    k=59 - k = 4 \implies k = 5.
This yields the final value of kk.

Anahtar Kavram

Finding the area of a region defined by linear boundary equations and dividing it with a vertical line.

Alternatif Yöntem

Using similar triangles: The right-hand triangle formed by the line x=3x = 3, the line y=x+9y = -x + 9, and the xx-axis has vertices at (3,0)(3,0), (9,0)(9,0), and (3,6)(3,6), with an area of 12×6×6=18\frac{1}{2} \times 6 \times 6 = 18. The smaller triangle to the right of x=kx = k has an area of 88 and is similar to the larger triangle. The ratio of their areas is 818=49\frac{8}{18} = \frac{4}{9}, which means the ratio of their linear dimensions is 49=23\sqrt{\frac{4}{9}} = \frac{2}{3}. The base of the larger triangle is 93=69 - 3 = 6, so the base of the smaller triangle must be 6×23=46 \times \frac{2}{3} = 4. This gives 9k=4    k=59 - k = 4 \implies k = 5.
Tahmini Süre:2m 30s
Soru 73Soru

A circle in the standard (x,y)(x, y) coordinate plane has center (3,4)(3, -4) and passes through the point (6,0)(6, 0). Which of the following is an equation of this circle?

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Cevap: x2+y26x+8y=0x^2 + y^2 - 6x + 8y = 0

Cevap

x2+y26x+8y=0x^2 + y^2 - 6x + 8y = 0
The standard equation of a circle is (xh)2+(yk)2=r2(x - h)^2 + (y - k)^2 = r^2, where (h,k)(h, k) is the center and rr is the radius. Given the center is (3,4)(3, -4), the equation becomes (x3)2+(y+4)2=r2(x - 3)^2 + (y + 4)^2 = r^2. Since the circle passes through (6,0)(6, 0), we substitute these coordinates to find r2r^2: (63)2+(0+4)2=32+42=9+16=25(6 - 3)^2 + (0 + 4)^2 = 3^2 + 4^2 = 9 + 16 = 25. The equation is therefore (x3)2+(y+4)2=25(x - 3)^2 + (y + 4)^2 = 25. Expanding this equation gives x26x+9+y2+8y+16=25x^2 - 6x + 9 + y^2 + 8y + 16 = 25. Combining constant terms yields x2+y26x+8y+25=25x^2 + y^2 - 6x + 8y + 25 = 25. Subtracting 25 from both sides results in the general form equation x2+y26x+8y=0x^2 + y^2 - 6x + 8y = 0.

Adım Adım Çözüm

1
Calculate the radius squared of the circle using the distance formula between the center (3,4)(3, -4) and the point on the circle (6,0)(6, 0).
r2=(63)2+(0(4))2=32+42=9+16=25r^2 = (6 - 3)^2 + (0 - (-4))^2 = 3^2 + 4^2 = 9 + 16 = 25
The distance between the center and any point on the circle is equal to the radius of the circle.
2
Write the standard form of the circle's equation using the center (h,k)=(3,4)(h, k) = (3, -4) and the radius squared r2=25r^2 = 25.
(x3)2+(y+4)2=25(x - 3)^2 + (y + 4)^2 = 25
The standard equation of a circle is (xh)2+(yk)2=r2(x - h)^2 + (y - k)^2 = r^2.
3
Expand the squared binomials in the standard equation to convert it into general form.
x26x+9+y2+8y+16=25x^2 - 6x + 9 + y^2 + 8y + 16 = 25
Expanding allows us to combine like terms and match the general form expressions in the options.
4
Simplify the expanded equation by combining constant terms and setting the equation to zero.
x2+y26x+8y+25=25x2+y26x+8y=0x^2 + y^2 - 6x + 8y + 25 = 25 \Rightarrow x^2 + y^2 - 6x + 8y = 0
Subtracting 25 from both sides yields the final simplified general form equation of the circle.

Anahtar Kavram

Deriving and expanding the equation of a circle from its center and a point.
Soru 74Soru

In the standard (x,y)(x, y) coordinate plane, line jj has the equation y=14x+7y = -\frac{1}{4}x + 7. If line kk is perpendicular to line jj, what is the slope of line kk?

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Cevap: 4

Cevap

The slope of line kk is 4.
The slope of the perpendicular line is 44 because the negative reciprocal of the given slope, 14-\frac{1}{4}, is 44.

Adım Adım Çözüm

1
Identify the slope of line jj.
The slope of line jj is 14-\frac{1}{4}.
The equation of line jj is given in slope-intercept form, y=mx+by = mx + b, where the coefficient of xx represents the slope.
2
Calculate the negative reciprocal of the slope of line jj to find the slope of perpendicular line kk.
The slope of line kk is 44.
Perpendicular lines have slopes that are negative reciprocals of each other. The negative reciprocal of 14-\frac{1}{4} is 114=4-\frac{1}{-\frac{1}{4}} = 4.

Anahtar Kavram

The slopes of perpendicular lines are negative reciprocals of each other.
Tahmini Süre:45s
Soru 75Soru

In the standard (x,y)(x,y) coordinate plane, point PP has coordinates (3,2)(3, 2). If point PP is reflected across the yy-axis and then translated 44 units up to create point PP', what are the coordinates of PP'?

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Cevap: (3,6)(-3, 6)

Cevap

The coordinates (3,6)(-3, 6)
Reflecting the point (3,2)(3, 2) across the yy-axis changes the sign of the xx-coordinate, producing (3,2)(-3, 2). Translating this resulting point 44 units up adds 44 to the yy-coordinate, giving the final coordinates (3,6)(-3, 6).

Adım Adım Çözüm

1
Reflect the point P(3,2)P(3, 2) across the yy-axis.
The xx-coordinate changes sign, while the yy-coordinate remains unchanged, yielding (3,2)(-3, 2).
A reflection across the yy-axis maps any point (x,y)(x, y) to (x,y)(-x, y).
2
Translate the point (3,2)(-3, 2) up by 44 units.
Add 44 to the yy-coordinate: 2+4=62 + 4 = 6, yielding (3,6)(-3, 6).
A translation of dd units upward maps any point (x,y)(x, y) to (x,y+d)(x, y + d).

Anahtar Kavram

Applying a sequence of transformations to a point in the coordinate plane by first reflecting it across an axis and then translating it.
Soru 76Soru

A linear model predicts the height of a plant, HH, in inches, based on the number of weeks, ww, since it was planted. According to the model, the height of the plant after 22 weeks is 3123\frac{1}{2} inches, and its height after 44 weeks is 4144\frac{1}{4} inches. What was the initial height of the plant, in inches, when it was planted?

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Cevap: 2342\frac{3}{4}

Cevap

The initial height of the plant was 2342\frac{3}{4} inches.
The correct answer is 2342\frac{3}{4} inches. First, the two given data points are (2,72)(2, \frac{7}{2}) and (4,174)(4, \frac{17}{4}). The rate of growth (slope) is calculated as m=1747242=38m = \frac{\frac{17}{4} - \frac{7}{2}}{4 - 2} = \frac{3}{8} inches per week. Substituting this into the slope-intercept form equation H=mw+bH = mw + b at w=2w = 2 gives 72=38(2)+b\frac{7}{2} = \frac{3}{8}(2) + b, which simplifies to b=7234=234b = \frac{7}{2} - \frac{3}{4} = 2\frac{3}{4} inches.

Adım Adım Çözüm

1
Convert the mixed numbers for the plant heights into improper fractions.
The height at 22 weeks is 312=723\frac{1}{2} = \frac{7}{2} inches, and the height at 44 weeks is 414=1744\frac{1}{4} = \frac{17}{4} inches.
Improper fractions are easier to use in slope and linear equation calculations.
2
Calculate the slope (weekly growth rate) of the linear function using the formula m=H2H1w2w1m = \frac{H_2 - H_1}{w_2 - w_1}.
m=1747242=342=38m = \frac{\frac{17}{4} - \frac{7}{2}}{4 - 2} = \frac{\frac{3}{4}}{2} = \frac{3}{8}
The slope represents the constant rate of height increase per week.
3
Use the slope-intercept form H=mw+bH = mw + b and substitute one of the points to solve for the y-intercept, bb.
Using the point (2,72)(2, \frac{7}{2}): 72=38(2)+b72=34+bb=7234=14434=114=234\frac{7}{2} = \frac{3}{8}(2) + b \Rightarrow \frac{7}{2} = \frac{3}{4} + b \Rightarrow b = \frac{7}{2} - \frac{3}{4} = \frac{14}{4} - \frac{3}{4} = \frac{11}{4} = 2\frac{3}{4}
The y-intercept, bb, represents the initial height of the plant at w=0w = 0 weeks.

Anahtar Kavram

Determining the equation of a line from two points and finding the y-intercept in a real-world context.
Soru 77Soru

In the standard (x,y)(x, y) coordinate plane, line L1L_1 is defined by the equation 3xky=83x - ky = 8, where kk is a non-zero constant. Line L2L_2 is perpendicular to L1L_1 and passes through the points (k,2)(k, 2) and (1,k+5)(-1, k+5). What is the sum of all possible real values of kk?

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Cevap: 22

Cevap

The sum of all possible real values of kk is 22.
The slope of line L1L_1 is found by converting its equation to slope-intercept form, yielding m1=3km_1 = \frac{3}{k}. Since line L2L_2 is perpendicular, its slope must be the negative reciprocal, m2=k3m_2 = -\frac{k}{3}. Using the slope formula with the given points on line L2L_2, we also have m2=(k+5)21k=k+3k+1m_2 = \frac{(k+5) - 2}{-1 - k} = -\frac{k+3}{k+1}. Setting these two expressions for m2m_2 equal to each other and solving the resulting proportion gives the quadratic equation k22k9=0k^2 - 2k - 9 = 0. The discriminant of this equation is positive (40>040 > 0), confirming the existence of two real solutions. By Vieta's formulas, the sum of the roots is ba=21=2-\frac{b}{a} = -\frac{-2}{1} = 2.

Adım Adım Çözüm

1
Determine the slope of line L1L_1 in terms of kk.
The slope of line L1L_1 is m1=3km_1 = \frac{3}{k}.
Rewriting the equation 3xky=83x - ky = 8 in slope-intercept form (y=mx+by = mx + b) gives ky=3x8ky = 3x - 8, which simplifies to y=3kx8ky = \frac{3}{k}x - \frac{8}{k}. The coefficient of xx represents the slope of the line.
2
Find the perpendicular slope m2m_2 of line L2L_2 in terms of kk.
The slope of line L2L_2 is m2=k3m_2 = -\frac{k}{3}.
Since line L2L_2 is perpendicular to line L1L_1, its slope must be the negative reciprocal of m1m_1 (i.e., m2=1m1m_2 = -\frac{1}{m_1}).
3
Express the slope of line L2L_2 using the two given points (k,2)(k, 2) and (1,k+5)(-1, k+5).
The slope of line L2L_2 is m2=k+3k+1m_2 = -\frac{k+3}{k+1}.
Using the slope formula m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1} with the points (k,2)(k, 2) and (1,k+5)(-1, k+5), we get m2=(k+5)21k=k+3(k+1)=k+3k+1m_2 = \frac{(k+5) - 2}{-1 - k} = \frac{k+3}{-(k+1)} = -\frac{k+3}{k+1}.
4
Set the two expressions for the slope of line L2L_2 equal to each other and solve for kk.
The quadratic equation is k22k9=0k^2 - 2k - 9 = 0.
Equating the slopes gives k3=k+3k+1-\frac{k}{3} = -\frac{k+3}{k+1}. Multiplying both sides by 1-1 gives k3=k+3k+1\frac{k}{3} = \frac{k+3}{k+1}. Cross-multiplying yields k(k+1)=3(k+3)    k2+k=3k+9    k22k9=0k(k+1) = 3(k+3) \implies k^2 + k = 3k + 9 \implies k^2 - 2k - 9 = 0.
5
Calculate the sum of all possible real values of kk.
The sum of all possible real values of kk is 22.
The discriminant of the quadratic equation k22k9=0k^2 - 2k - 9 = 0 is (2)24(1)(9)=40>0(-2)^2 - 4(1)(-9) = 40 > 0, confirming that two distinct real solutions for kk exist. According to Vieta's formulas, the sum of the roots of a quadratic equation ax2+bx+c=0ax^2 + bx + c = 0 is ba-\frac{b}{a}. Here, a=1a=1 and b=2b=-2, so the sum is 21=2-\frac{-2}{1} = 2.

Anahtar Kavram

Perpendicular lines have slopes that are negative reciprocals of each other (m1m2=1m_1 \cdot m_2 = -1).
Soru 78Soru

A scientist maps the movement of a cell on a coordinate grid. The cell is initially located at the point (2,5)(2, -5). The cell then moves to a new position after being translated 6 units to the left and 4 units up. What are the coordinates of the cell's new position?

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Cevap: (4,1)(-4, -1)

Cevap

The correct position of the cell is (4,1)(-4, -1).
To find the coordinates of the new position, apply the translation to the initial coordinates (2,5)(2, -5). A translation of 6 units to the left subtracts 6 from the x-coordinate: 26=42 - 6 = -4. A translation of 4 units up adds 4 to the y-coordinate: 5+4=1-5 + 4 = -1. This results in the coordinates (4,1)(-4, -1).

Adım Adım Çözüm

1
Calculate the new x-coordinate by applying the horizontal translation.
The initial x-coordinate is 22. Translating 6 units to the left means subtracting 6: 26=42 - 6 = -4.
A horizontal shift to the left decreases the x-coordinate value.
2
Calculate the new y-coordinate by applying the vertical translation.
The initial y-coordinate is 5-5. Translating 4 units up means adding 4: 5+4=1-5 + 4 = -1.
A vertical shift upward increases the y-coordinate value.
3
Combine the new coordinates into an ordered pair (x,y)(x, y).
The new coordinates are (4,1)(-4, -1).
The coordinates are represented by the new horizontal position followed by the new vertical position.

Anahtar Kavram

Translating a point in the coordinate plane by modifying its coordinates: (x,y)(x+h,y+k)(x, y) \rightarrow (x + h, y + k), where hh is the horizontal shift and kk is the vertical shift.
Soru 79Soru

In the standard (x,y)(x,y) coordinate plane, triangle PQRPQR has vertices P(2,3)P(2, 3), Q(6,3)Q(6, 3), and R(2,6)R(2, 6). The triangle undergoes a sequence of three transformations:

1. A dilation centered at the point (4,2)(4, 2) with a scale factor of 2-2.
2. A reflection across the line y=xy = -x.
3. A rotation of 9090^\circ counterclockwise about the origin.

What are the coordinates of the image of vertex RR after this sequence of transformations?

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Cevap: (8,6)(8, 6)

Cevap

The coordinate pair (8,6)(8, 6)
Applying the dilation formula centered at (4,2)(4, 2) with scale factor 2-2 to R(2,6)R(2, 6) gives the point R(8,6)R'(8, -6). Reflecting this point across the line y=xy = -x negates and swaps the coordinates, yielding R(6,8)R''(6, -8). Finally, a 9090^\circ counterclockwise rotation about the origin swaps the coordinates and negates the new xx-coordinate, producing the final coordinates (8,6)(8, 6).

Adım Adım Çözüm

1
Perform the dilation of vertex R(2,6)R(2, 6) centered at C(4,2)C(4, 2) with a scale factor of k=2k = -2.
The intermediate image is R(8,6)R'(8, -6).
For a dilation centered at (xc,yc)(x_c, y_c) with scale factor kk, the coordinates of the image are (xc+k(xxc),yc+k(yyc))(x_c + k(x - x_c), y_c + k(y - y_c)). Substituting R(2,6)R(2, 6), C(4,2)C(4, 2), and k=2k = -2 gives: x=42(24)=8x' = 4 - 2(2 - 4) = 8 and y=22(62)=6y' = 2 - 2(6 - 2) = -6.
2
Reflect the point R(8,6)R'(8, -6) across the line y=xy = -x.
The intermediate image is R(6,8)R''(6, -8).
A reflection across the line y=xy = -x maps any point (x,y)(x, y) to (y,x)(-y, -x). Applying this rule to R(8,6)R'(8, -6) yields R((6),8)=(6,8)R''(-(-6), -8) = (6, -8).
3
Rotate the point R(6,8)R''(6, -8) by 9090^\circ counterclockwise about the origin.
The final image is R(8,6)R'''(8, 6).
A rotation of 9090^\circ counterclockwise about the origin maps any point (x,y)(x, y) to (y,x)(-y, x). Applying this rule to R(6,8)R''(6, -8) yields R((8),6)=(8,6)R'''(-(-8), 6) = (8, 6).

Anahtar Kavram

Composite transformations in the coordinate plane combining dilation from a non-origin center, reflection across diagonal lines, and rotation about the origin.

Alternatif Yöntem

Instead of applying the transformations step-by-step to the point, we can track the transformations vectorially. For the dilation, the vector CR=RC=(2,4)\vec{CR} = R - C = (-2, 4) is scaled by 2-2 to get 2CR=(4,8)-2\vec{CR} = (4, -8), which added back to C(4,2)C(4, 2) yields R(8,6)R'(8, -6). Reflecting across y=xy = -x exchanges the coordinates and negates them, giving R(6,8)R''(6, -8). Rotating 9090^\circ counterclockwise about the origin maps (x,y)(y,x)(x, y) \rightarrow (-y, x), yielding R(8,6)R'''(8, 6).
Tahmini Süre:3m 0s
Soru 80Soru

A square PQRSPQRS has vertices at P(2,2)P(2, 2), Q(6,2)Q(6, 2), R(6,6)R(6, 6), and S(2,6)S(2, 6) in the coordinate plane. The square is first rotated 9090^\circ counterclockwise about the origin, and then translated such that the final image of vertex RR is located at (1,5)(1, 5). What are the coordinates of the final image of vertex PP after this sequence of transformations?

Cevabı ve açıklamayı göster

Cevap: (5,1)(5, 1)

Cevap

(5,1)(5, 1)
To find the coordinates of the final image of vertex P, we perform the transformations step-by-step. First, a 9090^\circ counterclockwise rotation about the origin maps any point (x,y)(x, y) to (y,x)(-y, x). Under this rotation, P(2,2)P(2, 2) maps to P(2,2)P'(-2, 2) and R(6,6)R(6, 6) maps to R(6,6)R'(-6, 6). Second, we find the translation vector by comparing the rotated vertex R(6,6)R'(-6, 6) to its final position R(1,5)R''(1, 5). The change in the x-coordinate is 1(6)=71 - (-6) = 7, and the change in the y-coordinate is 56=15 - 6 = -1. This represents a translation of 77 units right and 11 unit down, or the vector (7,1)(7, -1). Finally, applying this translation to the intermediate point P(2,2)P'(-2, 2) gives P(2+7,21)=(5,1)P''(-2 + 7, 2 - 1) = (5, 1).

Adım Adım Çözüm

1
Apply the 9090^\circ counterclockwise rotation about the origin to the vertices P(2,2)P(2, 2) and R(6,6)R(6, 6).
Using the rotation rule (x,y)(y,x)(x, y) \rightarrow (-y, x), vertex P(2,2)P(2, 2) maps to P(2,2)P'(-2, 2) and vertex R(6,6)R(6, 6) maps to R(6,6)R'(-6, 6).
This establishes the intermediate positions of the vertices before the translation is applied.
2
Determine the translation vector (h,k)(h, k) that maps the intermediate point R(6,6)R'(-6, 6) to the final point R(1,5)R''(1, 5).
Solving the equations 6+h=1-6 + h = 1 and 6+k=56 + k = 5 gives h=7h = 7 and k=1k = -1. The translation vector is (7,1)(7, -1).
The translation shifts all points in the plane by the same distance and direction.
3
Apply the translation vector (7,1)(7, -1) to the intermediate vertex P(2,2)P'(-2, 2) to find the final image PP''.
P=(2+7,21)=(5,1)P'' = (-2 + 7, 2 - 1) = (5, 1).
Applying the same translation to the rotated position of vertex P yields its final coordinates.

Anahtar Kavram

Composite transformations in the coordinate plane
Tahmini Süre:2m 0s
ÖncekiSayfa 4 / 14Sonraki