### Home > A2C > Chapter 9 > Lesson 9.3.2 > Problem9-162

9-162.

Use your knowledge of the unit circle to explain why the graphs of $y = \operatorname{sin}θ$ and $y = \operatorname { cos } ( \theta - \frac { \pi } { 2 } )$are the same.

When you find the complement of the angle, the x and y-values reversed.