How do you integrate int (e^x+e^-x)/(e^x-e^-x)dxex+exexexdx?

1 Answer
Feb 20, 2017

int (e^x + e^-x)/(e^x - e^-x)dx = ln|sinhx| + C = ln|1/2(e^x -e^-x)| + Cex+exexexdx=ln|sinhx|+C=ln12(exex)+C

Explanation:

We know that

•coshx = (e^x + e^-x)/2coshx=ex+ex2
•sinhx = (e^x- e^-x)/2sinhx=exex2

This integral can be rewritten as

int coshx/sinhx dxcoshxsinhxdx, where coshxcoshx and sinhxsinhx represent the hyperbolic trigonometric functions

Now use a substitution to solve. Let u = sinhxu=sinhx. Just like with regular trigonometric functions, du = coshx dxdu=coshxdx and dx= (du)/coshxdx=ducoshx.

int coshx/u * (du)/coshx coshxuducoshx

int 1/u du1udu

ln|u| + Cln|u|+C

ln|sinhx| + Cln|sinhx|+C

If you wish, the answer can be written as

ln|1/2(e^x - e^-x)| + Cln12(exex)+C

Hopefully this helps!