Derivatives Plz Help I'm close to dropping but this is required

Question

f(x) = 3 sin(x) + 11 cos(x)

f ' (x) =

f ' (7pi/4) =

Answer 1

The derivative of sin(x) = cos(x)

The derivative of cos(x) = -sin(x)

Let k be any constant. The derivative of k*f(x) = k*f'(x). So the derivative for example of 17*sin(x) = 17* cos(x)

The derivative of a sum is the sum of the derivative.

Putting this all together you can now solve your question.