Question

How do you find the derivative of `f(x)= 3cos(2x) + sin(2x)`?

Answer 1

You can use the Chain Rule to deal with the arguments of `cos` and `sin` deriving first the trigonometric function as it is and then multiply by the derivative of the argument getting:

`f'(x)=[-3sin(2x)]*2+[cos(2x)]*2=`

`=-6sin(2x)+2cos(2x)`