1.

Evaluate \(\begin{vmatrix}-sinθ&-1\\1&sin⁡θ\end{vmatrix}\).(a) cos^2⁡θ(b) -cos^2⁡θ(c) cos⁡2θ(d) cos⁡θThe question was posed to me in an international level competition.My query is from Determinant topic in division Determinants of Mathematics – Class 12

Answer»

The correct OPTION is (a) cos^2⁡θ

The best I can explain: EXPANDING along R1, we get

∆=-sinθ(sinθ)-(-1)1=-sin^2⁡θ+1=cos^2⁡θ.



Discussion

No Comment Found

Related InterviewSolutions