# Integration by Substitution!

• Jan 13th 2010, 06:01 AM
littlesohi
Integration by Substitution!
I don't know which of the factores to pick out as the "u"

1. integral of e ^x/2

2. integral of ln4xdx/x

thanks!
• Jan 13th 2010, 06:07 AM
dedust
Quote:

Originally Posted by littlesohi
I don't know which of the factores to pick out as the "u"

1. integral of e ^x/2

2. integral of ln4xdx/x

thanks!

1. $u = \frac{x}{2}$

2. $u = \ln 4x$