# How do you determine whether the function #f(x)= sinx-cosx# is concave up or concave down and its intervals?

##### 1 Answer

Oct 25, 2015

See the explanation section.

#### Explanation:

This happens at

For

For

Both sine and cosine are periodic with period

on intervals of the form

on intervals of the form

There are, of course other ways to write the intervals.