Question

Trigonometry
Establish the identity

cot^2 u/2 = csc u + cot u/csc u - cot u

Answer 1

\[\tan u/2 =\frac{ sinu }{ 1+cosu }\]
\[\tan ^{2}u/2=\frac{ \sin ^{2} }{ (1+\cos ^{}u)^{2} }=\frac{ \sin ^{2}u }{ (1+2cosu+\cos ^{2}u )}\]

Answer 2

now \[\cot ^{2}u=\frac{ 1 }{ \tan ^{2}u }\]
use this