Question

1-tan^2A/ 1+ tan^2 A = 2 sin^2 A = 1-2sin^2 A​

Answer 1

=sec2A1−tan2A(∵sec2x=1+tan2x)=sec2A1−sec2Atan2A=cos2A−cos2A1cos2Asin2A(∵secx=cosx1,tanx=cosxsinx)=(1−sin2A)−(cos2Asin2A×cos2A)(∵1−sin2x=cos2x)=1−sin