Mathematics

The key insight is to use the complementary angle relationship: $\sin \theta = \cos(90° - \theta)$. Since $\sin 64° = \cos 26°$, you're really comparing $\cos 26°$ and $\cos 64°$. Because cosine is a decreasing function on $[0°, 180°]$, the larger angle gives the smaller cosine value—so $\cos 64° < \cos 26°$.

The key insight is to use the complementary angle relationship: $\sin \theta = \cos(90° - \theta)$. Since $\sin 64° = \cos 26°$, you're really comparing $\cos 26°$ and $\cos 64°$. Because cosine is a decreasing function on $[0°, 180°]$, the larger angle gives the smaller cosine value—so $\cos 64° < \cos 26°$.