How do you find the derivative of (tan3(x)+10)2?

1 Answer
Mar 4, 2018

I get 6tan2(x)sec2(x)(tan3(x)+10).

Explanation:

We use the chain rule, which states that

dfdx=dfdududx

Let u=tan3(x)+10, so we have f=u2, then dfdu=2u

We can also differentiate tan3(x) using the chain rule.

We let z=tan(x),f=z3, then dfdz=3z2, and dzdx=sec2(x).

So, the derivative of tan3(x) is 3z2sec2(x)=3tan2(x)sec2(x).

That is also the dudx.

Putting everything back together, we get

dfdx=2u3tan2(x)sec2(x)

Replacing back u=tan3(x)+10, we get

dfdx=2(tan3(x)+10)3tan2(x)sec2(x)

=6tan2(x)sec2(x)(tan3(x)+10)