The number of real solutions of the equation 

${\sin }^{-1}(\sum _{i=1}^{\infty }{x}^{i+1}-x\sum _{i=1}^{\infty }{\left(\frac{x}{2}\right)}^i)=\frac{\pi }{2}-{\cos }^{-1}(\sum _{i=1}^{\infty }{(-\frac{x}{2})}^i-\sum _{i=1}^{\infty }{(-x)}^i)$ lying in the interval $(-\frac{1}{2},\frac{1}{2})$ is ______.

(Here, the inverse trigonometric functions ${\sin }^{-1}x$ and ${\cos }^{-1}x$ assume values in $[-\frac{\pi }{2},\frac{\pi }{2}]$ and $[0,\pi ]$, respectively).