اگر تابع $f\left( x \right)=\left\{ \begin{matrix}
\begin{align}
& \frac{\sin x}{\sqrt{1-\cos x}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x\lt 0 \\
& a\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x=0 \\
\end{align} \\
\left[ x \right]+b\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x\gt 0 \\
\end{matrix} \right.$ در نقطه صفر پیوسته باشد، مقدار $a+b$، کدام است؟