3.

Suppose the second derivative of f is given by f\"(x) = 40x7(x 7)3(x2 + 64). Determine the intervals of concavity of f. Enter your answer using interval notation. If an answer does not exist, enter DNE. f is concave up on |:| x Suppose the second derivative of f is given by f"(x) = 40(x - 3)4(x2 - 36). Determine the intervals of concavity of f. Enter your answer using interval notation. If an answer does not exist, enter DNE. f is concave up on X f is concave down on X