Question

(d) (1 + cos a) (1 - cos a) /(1 + sin a) (1 - sin a)= tan2 a​

Answer 1

`((1 - \cos(a))(1 + \cos(a)) )/((1 - \sin(a) )(1 + \sin(a)) ) = \\`

`\frac{1 - {cos}^(2)(a) }{1 - {sin}^(2)(a) } = \\`

`\frac{ {sin}^(2)(a) }{ {cos}^(2)(a) } = \\`

`{tan}^(2) (a)`