Solution
Correct Answer: Option D
দেওয়া আছে
1+ sinθ = m cos θ
বা, (1 + sinθ)/cosθ = m
বা, (1/cosθ) + (sinθ/cosθ) = m
বা, secθ + tanθ = m ...............(i)
আমরা জানি
(secθ + tanθ) (secθ - tanθ) = 1
বা, m(secθ - tanθ) = 1
বা, secθ - tanθ = 1/m .................(ii)
(i) - (ii) ⇒
secθ + tanθ - (secθ - tanθ) = m - 1/m
বা, secθ + tanθ - secθ + tanθ = (m2 - 1)/m
বা, 2tanθ = (m2 - 1)/m
বা, tanθ = (m2 - 1)/2m
বা, 1/cotθ = 1/{(m2 - 1)/2m}
∴ cotθ = 2m/(m2 - 1)