1. The problem statement, all variables and given/known data f(x) = 2x2 + 4e(5x) is invertible. Give the slope of the normal line to the graph of f-1 at x = 4. 2. Relevant equations (Given in question) 3. 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.