Math, asked by Jimba, 1 year ago

4sina sin(60-a) sin(60+a)= sin3a


Jimba: Nice

Answers

Answered by siddhartharao77
95
Given 4 sin a sin(60-a) sin(60 + a) can be written as

           4 sin a ((sin 60 - a) + sin (60 - a))

           4 sin a(sin^2 60 - sin^2 a)

           4 sin a((root 3/2)^2 - sin ^2 a)

           4 sin a(3/4 - sin^2 a)

           4 ( 3 sin a - 4 sin^3 a/4)

           4(1/4(sin 3a)

            sin 3a.

nikhil177: tnks
siddhartharao77: :-))
Answered by GauravGumber
73
4 sin a sin (60- a) sin (60 + a )

As Sin ( a- b ) sin ( a+b ) = sin²a - sin² b


4 Sin a * [ Sin² 60 - Sin² a ]

4 Sin a * [ 3/4 - Sin ² a ]

3 Sin a - 4 Sin ³ a = Sin 3a



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