Question

Which of the following would be the best first step for verifying the identity below?

tan^(2) y (csc^(2) y - 1) = 1

A. tan^(2) y (cot^(2)y) = 1
B. tan^(2) y (csc^(2) y -1) = sin^(2) y + cos^(2) y
C. (1/coy y)(csc^(2) y-1) = sin^(2) y + cos^(2) y
D. tan^(2) y ((1/sin y) - 1) = 1

Answer 1

Alright, Let's try to change the equation.

Then stay:

Tg^2y.(Csc^2y-1) = 1

This is easy to know, because:

Sin^2y + Cos^2y = 1

Then,

Tg^2y.(Csc^2y-1) = Sin^2y + Cos^2y

Then would be letter B)