Question 89
Let $ABC$ be a triangle such that $|AB| = 4$, $|BC| = 7$, $|CA| = 5$, and let $\alpha = \angle BAC$. Determine
$$
\sin^6 \frac{\alpha}{2} + \cos^6 \frac{\alpha}{2}.
$$
$$
\sin^6 \frac{\alpha}{2} + \cos^6 \frac{\alpha}{2}.
$$
MathNet 2019-part-02 — 184 problems (EN–VI) Question 89
Math Olympiad Vault · MathNet 2019-part-02 — 184 problems (EN–VI)