𝑓(𝑥)=4+5𝑥 with 𝑥∈(−4,8).

Answer 1

f(x) = 5x+4

f'(x) = 5

so the derivative is always 5 and never zer0.

the absolute max is 5(7)+4 = 39 and the absolute min is 5(-3) + 4 = -11