Matrices · Classes 11, 12
2 by 2 Matrix Inverse
Inverse exists when determinant is not zero.
FORMULA
\(A^{-1}=\frac1{ad-bc}\begin{bmatrix}d&-b\\-c&a\end{bmatrix}\)
Worked example
[[1,2],[3,4]] has determinant −2.
Understand this formula
Inverse exists when determinant is not zero.
Check measurement units, mathematical domains and rounding before applying any result in an examination.