6. Where is the curve () = ^3 8 concave down?

7. Where does () = ^4 + 2 5 have a point of inflection? Justify.

8. Given the function () = 1/12 ^4 1/6 ^3 ^2 + 1, find the intervals of concavity and the inflection points.

9. Use the Second Derivative Test to find the local maximum and minimum values of the function () = 2^3 + 15^2 36x.

10. Is the following statement true? Explain. If (2) = (2) = 0, then there must be a point of inflection at = 2