Chapter 13.1A, Problem 19A

a. Use a drawing similar to Figure 19 to find the images of the following points under a $90°$ rotation counterclockwise about the origin:

i. $\left(2,3\right)$

ii. $\left(-1,2\right)$

iii. $\left(m,n\right)$ in terms of m and n

b. Show that under a half-turn with the origin as center, the image of a point with coordinates $\left(a,b\right)$ has coordinates $\left(-a,-b\right)$.

c. Use what you found in part (a) to get the image of $P\left(a,b\right)$ under rotation clockwise by $90°$ about the origin.(Hint: Rotate first as in part (a), then apply a half-turn about the origin.)