Trig integrals

**XplicitZero** · June 23rd 2009, 04:51 PM

so i tried the problem

got ln(sec(4x)) & -2cos(4x)

what am i doing wrong?

**artvandalay11** · June 23rd 2009, 06:02 PM

tried what problem?

**XplicitZero** · June 23rd 2009, 06:19 PM

Originally Posted by artvandalay11

tried what problem?

the y = is the actual question.

**artvandalay11** · June 23rd 2009, 06:21 PM

Originally Posted by XplicitZero

the y = is the actual question.

you need to know when tan(4x)=2sin(4x)?

**Prove It** · June 23rd 2009, 06:29 PM

No, the OP trying to integrate each function between the limits $\left(-\frac{\pi}{2}, \frac{\pi}{2}\right)$ .

**skeeter** · June 23rd 2009, 07:07 PM

Originally Posted by XplicitZero

so i tried the problem

got ln(sec(4x)) & -2cos(4x)

what am i doing wrong?

both odd functions with limits of integration from -a to a ... what's that tell you?

**XplicitZero** · June 23rd 2009, 07:09 PM

don't know =(

**skeeter** · June 23rd 2009, 07:11 PM

Originally Posted by XplicitZero

don't know =(

visualize the definite integral ... graph one of them and see for yourself.

**XplicitZero** · June 23rd 2009, 07:16 PM

the graph looks crazy. line + zig-zag, but i really dunno.

**skeeter** · June 23rd 2009, 07:38 PM

window is from $\left[-\frac{\pi}{12} \, , \, \frac{\pi}{12}\right]$

look at it ... what's the value of the definite integral?

Thread: Trig integrals