Use the image to answer the question.
A coordinate plane with four quadrants shows an x axis capped with arrows and ranging from negative 11 to 10 in 1 unit increments and a y axis capped with arrows and ranging from 12 to negative 12 in 1 unit increments. Points upper A, upper B, upper A prime, and upper B prime are plotted. A coordinate plane with four quadrants shows an x axis capped with arrows and ranging from negative 11 to 10 in 1 unit increments and a y axis capped with arrows and ranging from 12 to negative 12 in 1 unit increments. Point upper A is plotted as left parenthesis negative 3 comma 4 right parenthesis and point upper B is plotted as left parenthesis 2 comma negative 4 right parenthesis. The points are joined by a line that extends beyond the points and is capped with arrows at both ends. Point upper A prime is plotted as left parenthesis negative 6 comma 8 right parenthesis and point upper B prime is plotted as left parenthesis 4 comma negative 8 right parenthesis. The points are joined by a line that extends beyond the points and is capped with arrows at both ends.
Determine the scale factor used in the dilation of line AB , with a center point of dilation at the origin.
(1 point)
The scale factor is
.
3 answers
The length of line AB can be found using the distance formula:
AB = sqrt((x2 - x1)^2 + (y2 - y1)^2)
= sqrt((2 - (-3))^2 + (-4 - 4)^2)
= sqrt(5^2 + (-8)^2)
= sqrt(25 + 64)
= sqrt(89)
The length of line A'B' can also be found using the distance formula:
A'B' = sqrt((x2' - x1')^2 + (y2' - y1')^2)
= sqrt((4 - (-6))^2 + (-8 - 8)^2)
= sqrt(10^2 + (-16)^2)
= sqrt(100 + 256)
= sqrt(356)
Therefore, the scale factor is the ratio of the lengths:
scale factor = A'B' / AB
= sqrt(356) / sqrt(89)
≈ 1.89
The scale factor is approximately 1.89.
To determine the scale factor, we can compare the corresponding coordinates of points A and A' (both are on the line AB) when taking the center of dilation at the origin.
The coordinates of point A are (-3, 4) and the coordinates of point A' are (-6, 8).
To find the scale factor, we can calculate the ratio of the change in the x-coordinate and the change in the y-coordinate:
Change in x-coordinate: -6 - (-3) = -3
Change in y-coordinate: 8 - 4 = 4
Scale factor = Change in y-coordinate / Change in x-coordinate
= 4 / -3
= -4/3
Therefore, the scale factor is -4/3.