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8sin^2xcos^x=1-cos4x
asked Oct 19, 2017 in TRIGONOMETRY by clakin2 Rookie

1 Answer

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LHS

8sin^2xcos^x =2(4sin^2xcos^x)

                      =2(sinxcosx)^2

                       =2sin^2(2x)

RHS

1-cos4x=1-(cos^2(2x)-sin^2(2x))

             =1-cos^2(2x)+sin^2(2x)

             =sin^2(2x)+sin^2(2x)

             =2sin^2(2x)

LHS =RHS

Hence, proved

answered Oct 19, 2017 by homeworkhelp Mentor

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