need help integrating x^2cos(x^2)dx

**ihaveamathproblem** · March 26th 2008, 12:11 PM

i know that i need to use integration by parts but i am stuck on picking my u and dv

EDIT: the problem is the integral of 2xcos(x^2)dx sorry

**galactus** · March 26th 2008, 12:28 PM

At first glance, I thought this was a Fresnel integral. Which is more difficult. But it is actually much easier than that.

Just use substitution instead of parts.

$2\int{xcos(x^{2})}dx$

Let $u=x^{2}, \;\ du=2xdx$

$\int{cos(u)}du=sin(u)$

$=sin(x^{2})$

Thread: need help integrating x^2cos(x^2)dx

LinkBack

Thread Tools

Display

need help integrating x^2cos(x^2)dx

Similar Math Help Forum Discussions

(2cos(x/2)sin(x/2))/2cos^2(x/2)

Evaluate the integral of 2cos(lnt)dt

show that x^4 - 3x^2 + 1 = 0 when x is given as 2cos(π/5)

2cos²θ+6cosθ=3

8sin^2(v)-2cos(v)=5

Search Tags