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Question -

sin2┬а24o┬атАУsin2┬а6o┬а= (тИЪ5 тАУ 1)/8



Answer -

Let us consider LHS:

sin2┬а24o┬атАУ sin2┬а6o

we know, sin (A + B) sin (A тАУ B) = sin2A тАУsin2B

Then the above equation becomes,

sin2┬а24o┬атАУ sin2┬а6o┬а=sin (24o┬а+ 6o) тАУ sin (24o┬атАУ 6o)

= sin 30o┬атАУ sin 18o

= sin 30o┬атАУ (тИЪ5 тАУ 1)/4 [since, sin 18o┬а=(тИЪ5 тАУ 1)/4]

= 1/2 ├Ч (тИЪ5 тАУ 1)/4

= (тИЪ5 тАУ 1)/8

= RHS

Hence proved.

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