Let y=y(x) be the solution curve of the differential equation (1+ sin x) (d y)/(d x)+(y+1) cos x=0, y(0)=0. If the curve y=y(x) passes through the…

Let $\displaystyle y=y(x)$ be the solution curve of the differential equation $\displaystyle (1+\sin x) \frac{\mathrm{d} y}{\mathrm{~d} x}+(y+1) \cos x=0, y(0)=0$. If the curve $\displaystyle y=y(x)$ passes through the point $\displaystyle \left(\alpha, \frac{-1}{2}\right)$, then a value of $\displaystyle \alpha$ is :