Find the inverse of \(\begin{pmatrix} 3 & 5 \\ 1 & 2 \end{pmatrix}\)
FURTHER MATHEMATICS
WAEC 2020
Find the inverse of \(\begin{pmatrix} 3 & 5 \\ 1 & 2 \end{pmatrix}\)
- A. \(\begin{pmatrix} 5 & 1 \\ -3 & 2 \end{pmatrix}\)
- B. \(\begin{pmatrix} 2 & -5 \\ -1 & 3 \end{pmatrix}\)
- C. \(\begin{pmatrix} -5 & 2 \\ -1 & 3 \end{pmatrix}\)
- D. \(\begin{pmatrix} 5 & 1 \\ 2 & 3 \end{pmatrix}\)
Correct Answer: B. \(\begin{pmatrix} 2 & -5 \\ -1 & 3 \end{pmatrix}\)
Explanation
Let A = \(\begin{pmatrix} 3 & 5 \\ 1 & 2 \end{pmatrix}\)
|A| = (3 x 2 - 5 x 1)
= 6 - 5
= 1
A\(^{-1}\) = \(\begin{pmatrix} 2 & -5 \\ -1 & 3 \end{pmatrix}\)
Post an Explanation Or Report an Error
If you see any wrong question or answer, please leave a comment below and we'll take a look. If you doubt why the selected answer is correct or need additional more details? Please drop a comment or Contact us directly. Your email address will not be published. Required fields are marked *