Question

What are the coordinates of the image produced by applying the composition Ro,-270 degrees o Ro,-90 degrees to the point (–5, 4)?

A. (–5, 4)
B. (–4, –5)
C. (4, 5)
D. (5, –4)

Answer 1

On dealing with a rotation of -270 degrees or 90 degrees (both are equal to each other), it is necessary to know the relation between the x and y coordinates to know the new coordinate points of the rotated image. The rotation relation for a 90 degree rotation is:

R90 (x,y) = (-y , x)

Therefore, with that being applied to the point (-5,4), the new coordinate points of the rotated image would be: (-4,-5). Among the choices, the correct answer is B.