Question

Parts `a, c, & d`? (See image)

Answer 1

For part (a):

Recall that:

• `f` is increasing at `x=a` if `f'(a)>0`
• `f` is decreasing at `x=a` if `f'(a)<0`

That is, `f` is increasing when its derivative is positive and is decreasing when its derivative is negative.

So `f` is increasing on `(1,6)uu(8,oo)` and is decreasing on `(0,1)uu(6,8)`.

I don't have time to answer the next two parts but both of them deal with concavity and the second derivative. The second derivative will equal `0` when the DERIVATIVE of the first derivative equals `0`, which is when the first derivative has a horizontal tangent line.