cosec (67° + θ) — sec (23° — θ) = 0

7

Prove that:

sin (70°+θ) — cos (20° — θ) = 0

7

tan (55° — θ) — cot (35° + θ) = θ

7

cosec (65° + θ) — sec (25° —θ) — tan (55° — θ) + cot (35° + θ) =0

7

sin (50° +θ) — cos (40° — θ) + tan 1°tan 10°tan 80°tan 89° =1