test 1 practice p2

-1 0 1 3. [20 points| Find the inverse of the matrix [ -2 1 0 -1 10 using Gaunss- Jordan Elimination. (Other meth. ods may result in the loss of points. ) Solution: Typical row operations are shown below. -1 0 1j1 o0 0] -2 1 0j0 1 0| - -2 1 oL 0 1 0 -1 1 0jo o 1] -1 1 0/ 0 0 1 2+ C 0 1 -1/-1 0 1 cmssmsmensenal) 1 0 -1} -1 0 0 @-® |o 1 -2/-2 1 o0 0o 0o 1, 1 -1 1 0-1 1 The inverse is thus| |0 -1 2 1 -1 1 Grading: +5 points for the set-up. +10 points for the row operations, +5 points for indicat- ing the answer. Grading for common mistakes: —7 points for bad row operations; —5 points for only doing Ganssian Elimination; +10 points (total) for using another method correctly; +5 points (total) for using another method mcorrectly.