Given curve is y = (1+x)y + sin−1(sin2x) On differentiating w.r.t x, we get dxdy = (1+x)y[1+xy+log(1+x)dxdy] + 1−sin4x2sinxcosx ⇒ (dxdy)at (0,1) = 1 [Since at x = 0 , y = 1] Slope of normal at (x = 0) = -1 ∴ Equation of normal at x = 0 and y = 1 is y - 1 = - 1 (x - 0) ⇒ y - 1 = - x ⇒ x + y = 1