Integral

**strammer** · January 31st 2013, 11:36 AM

Prove that $\int_0^{\pi/4} d \phi e^{i \phi} e^{-R^2 \exp{(i 2 \phi)}} = 0$

**chiro** · January 31st 2013, 03:10 PM

Hey strammer.

Hint: Try using the substitution u = e^(i*theta).

**JJacquelin** · February 1st 2013, 02:09 AM

Originally Posted by strammer

Prove that $\int_0^{\pi/4} d \phi e^{i \phi} e^{-R^2 \exp{(i 2 \phi)}} = 0$

It is not possible to prove it because it is not true :
Another integral

**strammer** · February 1st 2013, 05:31 AM

Pardon me. It is only true as R tends to infinity.

**JJacquelin** · February 1st 2013, 05:56 AM

Obvious !

Thread: Integral