How to calculate the integral
restart; int(cos(a*x)*cos(x)^(a-2), x = 0 .. (1/2)*Pi) assuming a>1
with Maple? Mathematica 8.01 produces a very doubtful answer
In[1]:=Assuming[a > 1, Integrate[Cos[a*x]*Cos[x]^(a - 2), {x, 0, Pi}]]
Out[1]=((-1)^a* a* HypergeometricPFQ[{1, 1 - a, 1 + a}, {3/2, a}, 1/2]* Sin[a *[Pi]])/(-1 + a)
