# Thread: Matrices :D

1. ## Matrices :D

The question states determine whether the given matrix is invertible. If it is calculate the inverse:

$\begin{pmatrix} 1 & 1 & 1 & 1 \\1 & 2 & -1 & 2 \\1 & -1 & 2 & 1 \\1 & 3 & 3 & 2 \end{pmatrix}$

Ive tried it many times, but cant seem to get anywhere near what i should be getting.. Can anyone help?

2. The determinant of the matrix is -9, so the matrix is invertible.
To calculate the inverse, use Gauss elimination (Gaussian elimination - Wikipedia, the free encyclopedia) or Analytic solution (Invertible matrix - Wikipedia, the free encyclopedia)