Points A and B are at (4 ,6 )(4,6) and (7 ,5 )(7,5), respectively. Point A is rotated counterclockwise about the origin by pi/2 π2 and dilated about point C by a factor of 1/2 12. If point A is now at point B, what are the coordinates of point C?

1 Answer
Jun 8, 2018

color(green)("Coordinates of " C = (5,(3/2))Coordinates of C=(5,(32))

Explanation:

A(4,6), B(7,5), "counterclockwise rotation " A(4,6),B(7,5),counterclockwise rotation pi/2, "dilation factor" 1/2,dilation factor12

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New coordinates of A after (3pi)/23π2 counterclockwise rotation

A(4,6) rarr A' (-6,4)

vec (BC) = (1/2) vec(A'C)

b - c = (1/2)a' - (1/2)c

(1/2)c = -(1/2)a' + b

(1/2)C((x),(y)) = -(1/2)((-6),(4)) + ((7),(5)) = ((10),(3))

color(green)("Coordinates of " 2 *C ((10),3) = C(5,(3/2))