How do you evaluate the integral e4xdx?

1 Answer
Aug 13, 2014

We will use u-substitution, letting u=4x.

Thus, du=4dx.

Also, we will use the constant law of integration, namely Cf(x)dx=Cf(x)dx to rewrite the integral so that it contains du:

e4xdx=144e4xdx

Now, we will rewrite in terms of u:

e4xdx=14eudu

We know that the integral of eudu will simply be eu. Remember the constant of integration:

e4xdx=14eu+C

Substituting back u gives:

e4xdx=14e4x+C