Question

If cos A = 2 √

+1

then Prove that cosec A = +1

−1​

Answer 1

cos A+cos^2 A=1 ————(1)

cos A =1-cos^2 A

[sin^2 A=1- cos^2 A]

cos A= sin^2 A ———-(2)

Substitute value of cos A in Eqn. (1)

(sin^2 A) + (sin^2 A)^2=1

sin^2 A + sin^4 A=1 [Proved]