Question

having trouble with this problem, pls help :/ I know the answer, just not how to get there. (ap calc ab, integrals)

Answer 1

Answer: D) 101

Explanation:

By linearity, we can break it up into 2 integrals. The integral and derivative of f easily cancel out

`\int\limits^(10)_(-1) {(2x+0.5f'(x))} \, dx =\int\limits^(10)_(-1) {2x} \, dx +0.5\int\limits^(10)_(-1) {f'(x)} \, dx =x^2|^{^(10)}_{_(-1)}+0.5f(x)|^{^(10)}_{_(-1)}\\=(100-1)+0.5(f(10)-f(-1))=99+0.5(8-4))=101`

I used the table for values of f(x) at 10 and -1. Wouldn't be surprised if this was part of a series of questions about f because I really can't see how you could use the hypothesis that f is twice differentiable on R. Same for the other table values. I'm curious about how you found the answer. Was it a different way?