If sin θ + cos θ = p and sec θ + cosec θ = q. Prove that q(p² – 1) = 2p.

28

If , then prove .

29

Prove that (sin θ + sec θ )² + (cos θ + cosec θ )² = (1 + sec θ . cosec θ)².

31

Prove that .

32

If sin θ + 2 cos θ = 1, Prove that 2 sin θ –cos θ = 2.