Math, asked by Khushi0511, 1 year ago

Solve this question for Trigonometry Class 10th..

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Answered by mysticd
2
Hi ,

***********************************************
As we know the trigonometric identity

sin² A + cos² A = 1

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I'm using A instead of theta


LHS =( sin⁴ A + cos⁴ A )/ ( 1 - 2sin²Acos²A)


=[(sin² A)²+(cos² A)²

+2sin²Acos²A-2sin²Acos²A]/

( 1 - 2sin²Acos²A)

= [( sin² A + cos² A)² -2sin²Acos²A]/

(1-2sin²Acos²A)

= ( 1 - 2sin²Acos²A ) / ( 1 - 2sin²Acos²A )

= 1

= RHS

I hope this helps you.

:)

mysticd: to make the square we have to add and subtract the same term
mysticd: i.e + 2sin²Acos²A - 2sin²Acos²A
mysticd: then first 3terms = ( sin²A + cos² A)²
mysticd: remaining term is - 2sin²Acos²A
mysticd: is it clear now . give feed back
mysticd: :)
Answered by Anonymous
2

RHS

1- 2sin2teta*cos2teta

=(sin2teta+cos2teta)-2sin2teta*cos2teta

=sin2teta(1-2cos2teta)+cos2teta

=sin2teta(sin2teta+cos2teta-2cos2teta)+cos2teta

=sin2teta(sin2teta-cos2teta)+cos2teta

=sin4teta sin2teta*cos2teta+cos2teta

=sin4teta+cos2teta(1-sin2teta)

=sin4teta+cos2teta(sin2teta+cos2teta-sin2teta)

=sin4teta+cos2teta(+cos2teta)

=sin4teta+cos4teta

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