### Home > PC > Chapter 4 > Lesson 4.1.4 > Problem 4-57

4-57.

Consider the graphs of

*y*= sin(*x*+) and *y*= −sin*x*. Homework Help ✎Sketch both graphs on separate axes. What do you notice?

Sketch the graph of

*y*= cos(*x*+). What is it equivalent to? Use the unit circle to explain why adding

to the angle*x*reverses the sign of the*x*- and*y*-coordinates.

The first curve is shifted left *π* units.

The second curve is reflected vertically.

Look at the equations of the curves and the hint in part (a).