Question

could somebody please check my answer if it is correct. the question is: Find the derivative of y=e^-5x cos(4x-7)

Answer 1

f'(x) = e^-5x [-4sin(4x-7) - 5cos(4x-7)]

Answer 2

you can take -1 out as a common factor as well but otherwise it looks good to me

Answer 3

looks correct to me! good :)

Answer 4

thanks guys i really appreciate it

Answer 5

Or bury the -1 by writing as
\[e^{-5x}[4\sin(7-4x)-5\cos(7-4x)]\]