1.

Find k, if the following matrices are singular. \(\begin{vmatrix}k-1&2&3\\3&1&2\\1&-2&4\end{vmatrix}\)[(k-1, 2, 3) (3, 1, 2) (1, -2, 4)]

Answer»

Let A = \(\begin{vmatrix}k-1&2&3\\3&1&2\\1&-2&4\end{vmatrix}\)

Since A is a singular matrix |A| = 0

\(\begin{vmatrix}k-1&2&3\\3&1&2\\1&-2&4\end{vmatrix}\)

∴ (k – 1)(4 + 4) – 2(12 – 2) + 3 (-6 – 1) = 0 

∴ 8k-8-20-21 =0 

∴ 8k = 49 

∴ k = 49/8



Discussion

No Comment Found

Related InterviewSolutions