0} \atop {cos x<0}} \right\\ \left \{ {-2< x < 2}\atop{\frac{\pi}{2}+2 \pi n < x <\frac{3\pi}{2}+2\pi n " alt="cos x \sqrt{4-x^2}<0\\ \left \{ {{\sqrt{4-x^2}>0} \atop {cos x<0}} \right\\ \left \{ {-2< x < 2}\atop{\frac{\pi}{2}+2 \pi n < x <\frac{3\pi}{2}+2\pi n " align="absmiddle" class="latex-formula">
