If tan x


If $\tan x=-\frac{1}{\sqrt{5}}$ and $\theta$ lies in the IV quadrant, then the value of $\cos x$ is

(a) $\frac{\sqrt{5}}{\sqrt{6}}$

(b) $\frac{2}{\sqrt{6}}$

(c) $\frac{1}{2}$

(d) $\frac{1}{\sqrt{6}}$


(a) $\frac{\sqrt{5}}{\sqrt{6}}$

In the fourth quadrant, $\cos x$ and $\sec x$ are positive.

$\cos x=\frac{1}{\sec x}$

$=\frac{1}{\sqrt{\sec ^{2} x}}$

$=\frac{1}{\sqrt{1+\tan ^{2} x}}$




Leave a comment


Click here to get exam-ready with eSaral

For making your preparation journey smoother of JEE, NEET and Class 8 to 10, grab our app now.

Download Now