Question

please.answer i want...

Answer 1

1. Given, expression:

2( 1 + cosx ) - sin^2x

= 2 + 2cosx - sin^2x

= 1 + 1 + 2cosx - sin^2x

= 1 + 2cosx + ( 1 - sin^2x)

= 1 + 2cosx + cos^2x

= (1)^2 + 2 (1) (cosx) + ( cosx)^2

= (1 + cosx)^2

Answer: option (c) is correct.

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2. if sinx + sin^2x = 1 ,cos^2x + cos^4x = ?

sinx + sin^2x = 1 => sinx = 1 - sin^2x

sinx = cos^2x => cos^2x = sinx

cos^2x + cos^4x = cos^2x + ( cos^2x)^2

= sinx + ( sinx)^2

= sinx + sin^2x = 1

Answer: option (A) is correct.