Let f be the function given by f(x) = 2 cos x + 3ex. What is the value of f'(0)?

Question

Let f be the function given by f(x) = 2 cos x + 3e^x. What is the value of f'(0)?

A) -3

B) 0

C) 3

D) 5

Answer 1

d/dx (cos x) = -sin x, d/dx (e^x) = e^x

So find df/dx using these, then substitute x=0 into that

Answer 2

The derivative of 2cos(x) + 3exp(x) is

f' = -2sin(x) + 3exp(x)

Plug in x = 0 and you have your answer.