### Home > CALC > Chapter 5 > Lesson 5.2.3 > Problem 5-86

5-86.

The function *f*(*x*) is increasing when *f* '(*x*) > 0, and it is decreasing when *f* '(*x*) < 0.

The function is concave up when *f* ''(*x*) > 0, and it is concave down when *f* ''(*x*) < 0.