How do you differentiate 3sin^5(2x) using the chain rule?

1 Answer
Dec 30, 2015

30sin^4(2x)cos(2x)

Explanation:

The first issue is that the sine function is to the fifth power.

According to the chain rule, d/dx(u^5)=5u^4*(du)/dx.

So,

d/dx(3sin^5(2x))=5(3sin^4(2x))d/dx(sin(2x))

=>15sin^4(2x)*d/dx(sin(2x))

To find d/dx(sin(2x)), use the chain rule again:

d/dx(sin(u))=cos(u)*(du)/dx

Thus,

d/dx(sin(2x))=cos(2x)*d/dx(2x)=2cos(2x)

Plug this back in:

15sin^4(2x)*d/dx(sin(2x))

=>15sin^4(2x)*2cos(2x)

=>30sin^4(2x)cos(2x)