defence exam Coast Guard Navik GD (General Duty) 02/2025 Mock Test Series Mathematics Determinants Evaluation of Determinants
What is the value of \(\rm \begin{vmatrix}\cos 15{^\circ}&\sin 15{^\circ}\\\ \cos 45{^\circ} &\sin 45{^\circ}\end{vmatrix}\times \rm \begin{vmatrix}\cos 45{^\circ}&\cos 15{^\circ}\\\ \sin 45{^\circ} &\sin 15{^\circ}\end{vmatrix}\)?
1
\(\frac{1}{4}\)
2
\(\frac{\sqrt3}{2}\)
3
\(-\frac{1}{4}\)
4
\(-\frac{3}{4}\)