Suppose that on the interval [math], [math] is positive and concave up. Furthermore, assume that [math] exists and let [math]. Use this information to answer the following questions.

To answer the questions, choose your answers from the following list:

CU (concave up), CD (concave down), f(x) , f'(x) , f''(x) , 0 , or 1 .

a.) [math] on [math].

b.) [math], where [math] and [math] .

c.) [math] on [math].

d.) [math] is on [math].