Using an approach similar to that of Fig. 4.24 on page 64, show that a 180 poise

Question:

Using an approach similar to that of Fig. 4.24 on page 64, show that a 180° poise about the y-axis rotates vectors to mirror image positions with respect to the yz-plane.
[As in this figure, resolve the vector into its x- and y-components; however, for the case of a 180°(y) pulse, it is the y-component which is unaffected and the y-component which is inverted by the pulse.)