Maple procedure

1. Jan 27, 2010

latentcorpse

so i'm writing a maple procedure for the variational principle in quantum mechanics.

i have a function $f_1(x,\alpha)=\cos{\alpha x}$ for $|x| \leq \frac{\pi}{2 \alpha}$ and i need to compute $\left \langle f_1 | f_1 \right \rangle$

i have the code:

restart;
assume(x,real);
assume(hbar,positive);
assume(omega,positive);
assume(e,positive);
assume(alpha,positive);
assume(m,positive);
f1:=cos(alpha*x);
conjf1:=conjugate(f1);
normaliseint:=int(conjf1*f1,-Pi/(2*alpha)..Pi/(2*alpha));

now the andwer should be $\frac{\pi}{2}$ (i did it by hand) but Maple keeps giving me

$1/2\, \left( 2\,\cos \left( 1/2\,{\frac {\pi }{{\it \alpha}}} \right) \sin \left( 1/2\,{\frac {\pi }{{\it \alpha}}} \right) {\it \alpha}+\pi \right) {{\it \alpha}}^{-1}$

any ideas?
thanks.