Let R be the region enclosed by the curves y=6sin2x and y=6 over the segment [ π/2,3π/2]. Find the volume of the solid that is obtained by rotating R about the line y=−1.1.

i get V=451.7359646 but its wrong..

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then i found the antiderivative of sin4x and sin2x and got the final answer of the Volume. what did i mess up on?