cosec (67° + θ) — sec (23° — θ) = 0
Consider L.H.S.
= cosec (67° + θ) — sec (23° — θ)
= cosec (67° + θ) — sec (90° —(23° + θ))
= cosec (67° + θ) - cosec (67° + θ)
= 0
Hence, proved.