Question: Find the intervals on which the function $f(\mathrm{x})=2 \mathrm{x}^{3}-3 \mathrm{x}^{2}-36 \mathrm{x}+7$ is
(a) strictly increasing
(b) strictly decreasing.
Solution:
$F^{\prime}(x)<0$ for $x \in(-2,3)$
hence in this interval function is decreasing.
