1.

For which of the elements in the determinant Δ=\(\begin{vmatrix}1&8&-6\\2&-3&4\\-7&9&5\end{vmatrix}\) the cofactor is -37.(a) 4(b) 1(c) -6(d) -3I had been asked this question during an interview for a job.This intriguing question comes from Determinants in chapter Determinants of Mathematics – Class 12

Answer»

The correct option is (d) -3

To ELABORATE: Consider the element -3 in Δ=\(\begin{vmatrix}1&8&-6\\2&-3&4\\-7&9&5\end{vmatrix}\)

The cofactor of the element -3 is GIVEN by

A22=(-1)^2+2 M22

M22=\(\begin{vmatrix}1&-6\\-7&5\end{vmatrix}\)=1(5)-(-6)(-7)=5-42=-37

A22=(-1)^2+2 (-37)=-37.



Discussion

No Comment Found

Related InterviewSolutions