How would you solve these questions using Trigonomic Identities?

Question

sin^2x = tan^2x/1+tan^2x

sinx+cosx/tanx = 1/cosxtanx

Answer 1

1+tan^2 = sec^2
so, the Right side is

tan^2/sec^2
= sin^2/cos^2 * cos^2
= sin^2