Question

How do you differentiate `f(x)=sec(8x )` using the chain rule?

Answer 1

Please see the explanation section, below.

Explanation:

We know that `d/dx(secx) = secx tanx`

Applying the chain rule, we have

`d/dx(secu) = secutanu (du)/dx`

So, in this question, since `u=8x`, we get

`f'(x) = sec(8x)tan(8x) d/dx(8x)`

`= 8sec(8x)tan(8x)`