Question

If $\cos \theta =\frac{\sqrt{3}}{2}$, then find the value of acute angle $\theta$.

Answer 1

Given, $\cos \theta =\frac{\sqrt{3}}{2}$ ...(i)
But $\cos {30}^o=\frac{\sqrt{3}}{2}$ ...(ii)
From equations (i) and (ii)
$\cos \theta =\cos {30}^o$
$\therefore$ $\theta ={30}^o$.