prove differentiation formula y = cosec x then , dy/dx = d (cosec x) / dx = -cotx cosecx . Share with your friends Share 0 Manbar Singh answered this Let y = cosec x⇒y + ∆y = cosec x + ∆x⇒ ∆y = cosec x + ∆x - cosec x⇒∆y = 1sinx+∆x - 1sin x⇒∆y = sin x - sinx+∆xsinx+∆x . sin x⇒∆y = 2 cosx + x + ∆x2 . sinx - x - ∆x2sinx+∆x . sin x⇒∆y = 2 cosx + ∆x2 . sin-∆x2sinx+∆x . sin x⇒∆y =-2 cosx + ∆x2 . sin ∆x2sinx+∆x . sin x⇒∆y∆x = - 2 cos x + ∆x2 × 1sinx+∆x . sin x × sin∆x2∆x/2×12⇒lim∆x→0∆y∆x = -2 lim∆x→0cos x + ∆x2 × lim∆x→0 1sinx+∆x . sin x × 12×lim∆x→0sin∆x2∆x/2⇒dydx = - cos x × 1sin x . sin x × 1⇒ddxcosec x = -cos xsin x×1sin x⇒ ddxcosec x = - cot x . cosec x 0 View Full Answer
