Question

Find the derivative for
y=e^-2xcos(6x)

Answer 1

you need to product rule.

where \[h(x) = e^{-2x}\]

and

\[g(x) = \cos(6x)\]

so

\[\frac{dy}{dx} = g(x)\times h'(x) + h(x) \times g'(x)\]

Answer 2

Ok, so let me know if I'm on the right track.

dy/dx= cos(6x) * -2xe + e^-2x * 6xcos

Answer 3

that looks good except for the derivative of cos(6x)

dy/dx = -6sin(6x)