Question

(1 - cot theta) ^ 2 + (1 + cot theta) ^ 2 = 2cosec ^ 2 theta​

Answer 1

$\text{L.H.S}\\\\=(1 - \cot \theta )^2 + (1 + \cot \theta)^2 \\\\=(1-\cot \theta + 1 + \cot \theta)^2 - 2(1 -\cot \theta)(1 + \cot \theta)\\\\=2^2 - 2(1 - \cot^2 \theta)\\\\=4-2+2 \cot ^2 \theta\\\\=2+2 \cot^2 \theta\\\\=2(1 + \cot^2 \theta)\\\\=2 \csc^2 \theta\\\\=\text{R.H.S}\\\\\text{Proved.}$