- #1
JanClaesen
- 56
- 0
f(x) = cosh^2(x)+sinh(2x) = y
f'(x) = sinh(2x)+2cosh(2x) = 3e^(2x) + e^(-x) = y'
Let g(y) be the inverse of f(x):
g'(y) = 1 / f'(x) = 1 / [3e^(2y) + e^(-2y)] = e^(2y) / [4e^(2y) + 1]
Integrating gives: [ 3^(1/2)/3 ]*arctan[ 3^(1/2) * e^(2y) ] + C
Now when I plotted this function it looked in no way like the inverse of f(x), so where have I gone wrong?
Thank you
f'(x) = sinh(2x)+2cosh(2x) = 3e^(2x) + e^(-x) = y'
Let g(y) be the inverse of f(x):
g'(y) = 1 / f'(x) = 1 / [3e^(2y) + e^(-2y)] = e^(2y) / [4e^(2y) + 1]
Integrating gives: [ 3^(1/2)/3 ]*arctan[ 3^(1/2) * e^(2y) ] + C
Now when I plotted this function it looked in no way like the inverse of f(x), so where have I gone wrong?
Thank you