### Home > CALC > Chapter 3 > Lesson 3.4.4 > Problem3-190

3-190.

Determine algebraically where $y = x ^ { 3 } + \frac { 3 } { 2 } x ^ { 2 } - 6 x + 2$ is decreasing. Then, check with a graph of $y$ on your graphing calculator. How did a derivative help?

$y$ decreases where $y^\prime< 0$. Using this information, set up an inequality and solve it.