Originally Posted by
xxlvh #1. The functions f and g are differentiable. For all x, f(g(x)) = x and g(f(x)) = x. If f(3) = 8 and f'(3) = 9, what are the values of g(8) and g'(8)?
#2. The following values are given:
f(2.5) = 31.25
f(2.8) = 39.20
f(3.0) = 45
f(3.1) = 48.05
For the function f which is differentiable. Both f and f' are strictly increasing on the interval 0 < x < 5. Which of the following could be the value of f'(3)?
(A) 20
(B) 27.5
(C) 29
(D) 30
(E) 30.5
- originally, I tried to approximate f' by using the secant line and taking f(3.1) - f(2.8)/3.1 - 2.8 but ended up getting 29.5 as an answer..