# Let #f(x) = x^2 - 4x - 5#, x > 2, how do you find the value of #(df^-1)/dx# (or the derivative of the inverse of f(x)), at the point x = 0 = f(5)?

##### 1 Answer

Aug 8, 2016

#### Explanation:

we have

so if

to that end we can say that

and using the chain rule:

so

there's poss another way to show this, which is a bit of a desecration of the Liebnitz notation: ie