ExamBro
ExamBro
MHT CET · Maths · Matrices

The matrix \(A=\left[\begin{array}{ccc}a & -1 & 4 \\ -3 & 0 & 1 \\ -1 & 1 & 2\end{array}\right]\) is not invertible only if a =

  1. A -17
  2. B -16
  3. C 16
  4. D 17
Verified Solution

Answer & Solution

Correct Answer

(A) -17

Step-by-step Solution

Detailed explanation

(D)
Since \(\mathrm{A}\) is not invertible, \(|\mathrm{A}|=0\)
\(\begin{aligned} \therefore &\left|\begin{array}{ccc}a & -1 & 4 \\ -3 & 0 & 1 \\ -1 & 1 & 2\end{array}\right|=0\end{aligned}\)
\(\mathrm{a}(0-1)-(-1)(-6+1)+4(-3-0)=0 \Rightarrow-\mathrm{a}\) \(-5-12=0 \Rightarrow \mathrm{a}=-17\)
From MHT CET
Explore more questions on app