Question

${\cos }^{3}110^{\circ }+{\cos }^{3}10^{\circ }+{\cos }^{3}130^{\circ }=$

• A. $\frac{3}{4}$
• B. $\frac{3}{8}$
• C. $\frac{3\sqrt{3}}{8}$
• D. $\frac{3\sqrt{3}}{4}$

Answer 1

Answer: (C)

Correct answer is (c) $\frac{3\sqrt{3}}{8}$