$\lim_{x \to \frac{\pi}{2}} \tan^2 x \left[(2\sin^2 x + 3\sin x + 4)^{\frac{1}{2}} - (\sin^2 x + 6\sin x + 2)^{\frac{1}{2}}\right]$ is equal to (1) $\frac{1}{12}$ (2) $-\frac{1}{18}$ (3) $-\frac{1}{12}$ (4) $\frac{1}{6}$
$\lim_{x \to \frac{\pi}{2}} \tan^2 x \left[(2\sin^2 x + 3\sin x + 4)^{\frac{1}{2}} - (\sin^2 x + 6\sin x + 2)^{\frac{1}{2}}\right]$ is equal to\\
(1) $\frac{1}{12}$\\
(2) $-\frac{1}{18}$\\
(3) $-\frac{1}{12}$\\
(4) $\frac{1}{6}$