Find the inverse of the matrix A=(210121012)A = \begin{pmatrix} 2 & 1 & 0 \\ 1 & 2 & 1 \\ 0 & 1 & 2 \end{pmatrix}A=210121012.
14(3−21−24−21−23)\frac{1}{4} \begin{pmatrix} 3 & -2 & 1 \\ -2 & 4 & -2 \\ 1 & -2 & 3 \end{pmatrix}413−21−24−21−23
12(3−21−24−21−23)\frac{1}{2} \begin{pmatrix} 3 & -2 & 1 \\ -2 & 4 & -2 \\ 1 & -2 & 3 \end{pmatrix}213−21−24−21−23
(0.75−0.50.25−0.51−0.50.25−0.50.75)\begin{pmatrix} 0.75 & -0.5 & 0.25 \\ -0.5 & 1 & -0.5 \\ 0.25 & -0.5 & 0.75 \end{pmatrix}0.75−0.50.25−0.51−0.50.25−0.50.75
The matrix is singular.