Given equation is (cos p - 1) x2 + (cos p) x + sin p = 0 Since, the equation has real roots so, Δ = B2−4AC ≥ 0 ⇒ cos2p - 4 (cos p - 1) sin p ≥ 0 ⇒ cos2p 4 sin p . cos p + 4 sin p ≥ 0 ⇒ For real value of p (−4sinp)2 - 4 . 1 . (4 sin p) > 0 ⇒ 16sin2p - 16 sin p > 0 ⇒ sin p (sin p - 1) > 0 ⇒ sin p > sin 0 or sin p > sin