Verify the following trigonometric identities. In each case you might like to start with the most complicated side, and use algebraic manipulation to...

Verify the following trigonometric identities. In each case you might like to start with the most complicated side, and use algebraic manipulation to show that it can be written like the other side.

(a) tan²θ = tan² θ csc² θ − 1

(b) 1 − sinφ/cosφ = cosφ/1 + sinφ