Question #e21ad

1 Answer
Jun 18, 2017

dydx=3+sin(2x)log(2)(3xcos(2x))

Explanation:

First, use the "change of base" for logarithms formula

loga(b)=log(b)log(a)

Then take the derivative

ddx[log2(3xcos(2x))]=ddx[log(3xcos(2x))log(2)]

Factor out the constant

=1log(2)ddx[log(3xcos(2x))]

Use the Chain Rule on the derivative of the log function

=1log(2)×13xcos(2x)(ddx[3xcos(2x)])

=1log(2)×13xcos(2x)×(ddx[3x]ddx[cos(2x)])

=1log(2)×13xcos(2x)×(3(sin(2x)))

=1log(2)×13xcos(2x)×(3+sin(2x))

=3+sin(2x)log(2)(3xcos(2x))