- #1
Elixer
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Homework Statement
f(x) = 2x2 + 4e(5x)
is invertible. Give the slope of the normal line to the graph of f-1 at x = 4.
Homework Equations
(Given in question)
The Attempt at a Solution
I don't know how to solve this question. But , I found the following:-
f(4) = 32 + 4e20
let y = f-1(x), then
dy/dx = 1/f ' (y)
f ' (x) = 4x + 20e(5x)
Hence, dy / dx = 1/(4y + 20e(5y))
I don't know if I am heading in the right direction.
Please help!
Thank you.