3Part 1.
The critical values occur when
In our case, we have
Then, for x different from 2, this last equation yields
Therefore, the answer for part 1 is: x= 4 and x=-4
Part 2.
In order to see if the last points correspond to a minimum or maximim, we need to compute the seconde derivative of g. It is given by
Now, lets substitute the value x=4. It yields
and by substituting x= -4, we have
Since both solutions are greater than zero, they both correspond to a local minimum points.
Part 3.
From the last result, we can see that, on the interval
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