# What are the absolute extrema of #f(x) =x^4 − 8x^2 − 12 in[-3,-1]#?

##### 1 Answer

#### Answer:

#### Explanation:

Absolute extrema of a closed interval occur at the endpoints of the interval or at

That means we'll have to set the derivative equal to

So, starting with taking the derivative:

Setting it equal to

Thus the solutions are

We immediately get rid of

Finally, we evaluate these one by one to see what the absolute min and max are:

Therefore