### Home > INT3 > Chapter 9 > Lesson 9.2.2 > Problem 9-109

9-109.

Susan knows how to shift

*y*= sin(*x*) to get the graph at right, but she wonders if it is 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 writing a cosine function is possible, write an equation that has cosine. If you think writing one is impossible, explain why.

Adlai says,

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

Yes, it is.

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

*y* = −sin(*x*)