Re: [math-fun] An interesting definite integral?

Make the substitution y = x - pi/4. Then observe that cos(cos(3(x+pi/4))^2 is an even function but cos(2(x+pi/4)) is odd. On Fri, Nov 27, 2009 at 8:32 AM, Warut Roonguthai <warut822@gmail.com>wrote:

Numerically, I found that

\int_{0}^{\pi/2} \cos(2x)(\cos(\cos(3x)))^2 dx = 0,

but I couldn't prove it. So I post it here and hope some mathfunsters could shed some light on it.

Thanks, Warut

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