Answer
1
Work Step by Step
Given expression
= $ \sin^{2} 60^{\circ} + \cos^{2} 60^{\circ}$
= $ ( \sin 60^{\circ})^{2} + ( \cos 60^{\circ})^{2}$
= $ (\frac{\sqrt 3}{2})^{2} + (\frac{1}{2})^{2}$
( substituting for exact values of $ \sin 60^{\circ}$ and $ \cos 60^{\circ})$
=$ \frac{3}{4} + \frac{1}{4}$
= $\frac{(3+1)}{4}$
= $ \frac{4}{4}$
= 1
