integration

**christina** · January 12th 2010, 03:48 AM

Integrate:

2xe^(x^2)

AND

sinx/(2+cosx)

If anyone could help me with these two integrals it would be greatly appreciated, thank you !

**tonio** · January 12th 2010, 03:56 AM

Originally Posted by christina

Integrate:

2xe^(x^2)

AND

sinx/(2+cosx)

If anyone could help me with these two integrals it would be greatly appreciated, thank you !

Hints: for the first one, $\int f'(x)f(x)\,dx=\frac{f(x)^2}{2}+C(onstant)$

For the second one, $\int\frac{f'(x)}{f(x)}dx=\ln|f(x)|+C(onstant)$

Tonio

**mr fantastic** · January 12th 2010, 03:57 AM

Originally Posted by christina

Integrate:

2xe^(x^2) Mr F says: Substitute u = x^2.

AND

sinx/(2+cosx) Mr F says: Substitute u = 2 + cos x.

If anyone could help me with these two integrals it would be greatly appreciated, thank you !

..

**Shanks** · January 12th 2010, 04:04 AM

$\int 2xe^{x^2}dx=\int e^{x^2}dx^2=e^{x^2}+C$ .
similarly for the second one.

**HallsofIvy** · January 12th 2010, 05:11 AM

In other words, for the first one use the substitution $u= x^2$ and for the second, u= 2+ cos(x).

Thread: integration

LinkBack

Thread Tools

Display

integration

Similar Math Help Forum Discussions

Integration help please these are three small even basic integration problems

sketch the region of integration and change the order of integration.

Definite Integration - Double integration by parts

Simple Integration problem: Trigonometric Integration

Tricky integration, possibly Integration Factor

Search Tags