C-10-Q044mediumsingle_mcqcos30∘=?\cos 30^\circ = ?cos30∘=?a12\dfrac{1}{2}21b32\dfrac{\sqrt{3}}{2}23c12\dfrac{1}{\sqrt{2}}21d111ব্যাখ্যাcos30∘=32\cos 30^\circ = \dfrac{\sqrt{3}}{2}cos30∘=23 is a standard value. It equals sin60∘\sin 60^\circsin60∘ since 30∘30^\circ30∘ and 60∘60^\circ60∘ are complementary.