1.

The expression `3[sin^4(3/2pi-alpha)+sin^4(3pi+alpha)]-2[sin^6(1/2pi+alpha)+sin^6(5pi-alpha)]` is equal to

Answer» Correct Answer - B
`3[sin^4(3/2pi-alpha)+sin^4(3pi+alpha)]`
`-2[sin^6(1/2pi-alpha)+sin^6(5pi-alpha)]`
`=3(cos^4alpha+sin^4alpha)-2(cos^6alpha+sin^6alpha)`
`3(1-2sin^2alphacos^2alpha)-2[(sin^2alpha+cos^2alpha)^3`
`-3sin^2alphacos^2alpha(sin^2alpha+cos^2alpha)]`
`=3(1-2sin^2alphacos^2alpha)-2[1-3sin^2alphacos^2alpha]`
=1


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