1+sin^2(x)/cos^2(x)=2sec^2(-1)

Question

Prove the identity

Answer 1

sin2(x)/cos²(x) = tan²(x)

1+tan²(x) = sec²(x)

 

What you are probably looking for is

 

(cos²(x) + sin²(x))/(cos²(x)) = 1/cos²(x) = sec²(x)

 

Please check your notes.