C-09-Q171mediumsingle_mcq1−cot260∘1+cot260∘=?\dfrac{1 - \cot^2 60^\circ}{1 + \cot^2 60^\circ} = ?1+cot260∘1−cot260∘=?a−12-\dfrac{1}{2}−21b12\dfrac{1}{2}21c111d−1-1−1ব্যাখ্যাSince cot260∘=13\cot^2 60^\circ=\tfrac13cot260∘=31, the expression is 1−131+13=2/34/3=12\frac{1-\frac13}{1+\frac13}=\frac{2/3}{4/3}=\tfrac121+311−31=4/32/3=21.