Let $y = y(x)$ be the solution of the differential equation $\dfrac{2 + \sin x}{y+1} \cdot \dfrac{dy}{dx} = -\cos x,\; y > 0,\; y(0) = 1.$ If $y(\pi) = a$ and $\dfrac{dy}{dx}$ at $x = \pi$ is $b$, then the ordered pair $(a,b)$ is equal to :