Assistance Please - Thanks in advance

Question

Hello,

There are some questions that I am not sure how to tackle:

Prove the identities

1) (sinθ + cosθ)^2 - 2sinθ cosθ = 1

2) cosecθ (1 - cosθ) (1 + cosθ) = sinθ

3) cotθ secθ tanθ √(1 - sin^2θ) = 1

4) 1 / (sec^2θ) + 1 / cosec^2θ = 1

Thank you very much.

Answer 1

1) Left hand side identity

= Right hand side identity.

2) Left hand side identity

= Right hand side identity.

3) Left hand side identity

= Right hand side identity.

4) Left hand side identity

= Right hand side identity.