Estimate the largest eigenvalue of A=(1020281016)A = \begin{pmatrix} 10 & 2 & 0 \\ 2 & 8 & 1 \\ 0 & 1 & 6 \end{pmatrix}A=1020281016 using Gershgorin circles.
The largest eigenvalue is in the interval [10−2,10+2]=[8,12][10-2, 10+2] = [8, 12][10−2,10+2]=[8,12]
All eigenvalues are in [5,12][5, 12][5,12]
The largest eigenvalue is exactly 101010
The largest eigenvalue is in [11,12][11, 12][11,12]