# Substitution Rule

• June 28th 2010, 03:14 AM
centenial
Substitution Rule
I'm been working problems to help learn the substitution rule for integrals. Is this correct?

$\int\frac{{\sin{\ln{x}}}}{x}dx$

Let $u=\ln{x}$ and $du = \frac{1}{x}dx$.

$= \int{\sin{u}du}$
$= -\cos{u} + c$
$= -\cos{\ln{x}} + c$

Thanks,
• June 28th 2010, 03:29 AM
Chris L T521
Quote:

Originally Posted by centenial
I'm been working problems to help learn the substitution rule for integrals. Is this correct?

$\int\frac{{\sin{\ln{x}}}}{x}dx$

Let $u=\ln{x}$ and $du = \frac{1}{x}dx$.

$= \int{\sin{u}du}$
$= -\cos{u} + c$
$= -\cos{\ln{x}} + c$

Thanks,

Yes, that's correct.