Find the value of $\sin ^2 60^{\circ}+\cos ^2 30^{\circ}-\sin ^2 45^{\circ}-3 \sin ^2 90^{\circ}$.
Answer & explanation
Correct answer: option 4
sin²60º + cos²30º - sin²45º - 3sin²90º
= \(\frac{3}{4}\) + \(\frac{3}{4}\) - \(\frac{1}{2}\) - 3
= 1 - 3
= -2