Question

If ${\sin }^2\theta =\frac{1}{2},$ then find the value of $\cos \theta$

Answer 1

given that, ${\sin }^2\theta =\frac{1}{2}$

$\Rightarrow 1-{\sin }^2\theta =1-\frac{1}{2}=\frac{2-1}{2}$

$\Rightarrow {\cos }^2\theta =\frac{1}{2}$

$\Rightarrow \cos \theta =\pm \frac{1}{\sqrt{2}}$