Question

Is there anyone who's bored and wants to try finding the inverse of a matrix?

Answer 1

\[\left[\begin{matrix}1 & 2 \\ 5 & 9\end{matrix}\right]\]

Answer 2

\[\left[\begin{matrix}9 & -2 \\ -5 & 1\end{matrix}\right]\]

Answer 3

Is there a special process for two-by-two matrices?

Answer 4

yeah of course

Answer 5

\[\left[\begin{matrix}1 & 2 \\ 5 & 9\end{matrix}\right|\left.\begin{matrix}1 & 0 \\ 0 & 1\end{matrix}\right]=\left[\begin{matrix}1 & 0 \\ 0 & 1\end{matrix}\right|\left.\left(\begin{matrix}1 & 2 \\ 5 & 9\end{matrix}\right)^{-1}\right]\]

Answer 6

If \[\left[\begin{matrix}a & b \\ c & d\end{matrix}\right]\]is a matrix then its inverse is : -\[\left[\begin{matrix}d & -b \\ -c & a\end{matrix}\right]\]

Answer 7

gt it?

Answer 8

or use row operations to convert my LHS to my RHS

Answer 9

Oh. I never knew that. Ok. It always took me forever for inverses of matrices. Thanks :) And I do know how to find the inverse using the normal way.

Answer 10

this is a special case for only order 2 matrix
which i told u:)