Math, asked by Masuka9188, 2 months ago

Cos @ cos (60^°-@) cos(60^°+@) =1/4cos3@

Answers

Answered by panchakarlaswetha
0

Answer:

cosAcos(60−A)cos(60+A)=4cos3A

cos(x−y)cos(x+y)=cos2y−sin2x

cos3x=4cos3x−3cosx

cosAcos(60−A)cos(60+A)

=cosA(cos2(A)−sin260)

=cosA(cos2A−43)

=44cos3A−3cosA

=4cos3A

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