Question

If $\tan \theta =1$, then $\cos \theta$ will be:

• A. $1$
• B. $\frac{1}{2}$
• C. $\frac{\sqrt{3}}{2}$
• D. $\frac{1}{\sqrt{2}}$

Answer 1

The correct option is D $\frac{1}{\sqrt{2}}$

$\tan \theta =1$
$\Rightarrow \tan \theta =\tan {45}^o$
$\therefore \theta ={45}^o$
$\cos {45}^o=\frac{1}{\sqrt{2}}$