### Home > CCA2 > Chapter 7 > Lesson 7.2.4 > Problem 7-158

7-158.

Susan knew how to shift *y*= sin*x*to get the graph at right, but she wondered if it would be possible to get the same graph by shifting*y*= cos*x*. Homework Help ✎Is it possible to write a cosine function for this graph?

If you think it is possible, find an equation that does it. If you think it is impossible, explain why.

Adlai said,

*“I can get that graph*without*shifting to the right or left.”*What equation did he write?

Yes, it is.

The graph of *y* = cos *x* starts at a maximum. This graph has a maximum at

*y* = −sin(*x*)