Answer
Decreasing on $(-\infty,-1)\cup(0,1)$
Increasing on $(-1,0)\cup(1,\infty)$
Work Step by Step
We are given the function:
$f(x)=3x^4-6x^2$
Graph the function.
From the graph we find:
$f$ is decreasing on $(-\infty,-1)\cup(0,1)$
$f$ is increasing on $(-1,0)\cup(1,\infty)$
Check the result using a table of values:
