Question

How do I find the derivative of `y= arccos (e^7x)`?

Answer 1

The answer is: `y'=-e^7/sqrt(1-e^14x^2`

The derivative of the function: `y=arccosf(x)` is

`y'=-1/(sqrt(1-[f(x)]^2))*f'(x)`.

So:

`y'=-1/sqrt(1-(e^7x)^2)*e^7=-e^7/sqrt(1-e^14x^2)`.

A common error is considering `e^n` as a function, but it is only a number! Remember that the function is `e^x`!