Answer 1

cosec (65 + θ) = sec (90 – (65 + θ)) = sec (25 – θ)

tan (55 – θ) = cot (90 – (55 – θ) = cot (35 + θ)

⇒ sec (25 – θ) – sec (25 – θ) tan (55 – θ) + tan (55 – θ) = 0