8.8. EXERCISES 155
29. Let
A =
(0 15 3
).
Find A−1 if possible. If A−1 does not exist, determine why.
30. Let
A =
(2 13 0
).
Find A−1 if possible. If A−1 does not exist, determine why.
31. Let
A =
(2 14 2
).
Find A−1 if possible. If A−1 does not exist, determine why.
32. Let A be a 2×2 matrix which has an inverse. Say A =
(a bc d
). Find a formula
for A−1 in terms of a,b,c,d.
33. Let
A =
1 2 32 1 41 0 2
.
Find A−1 if possible. If A−1 does not exist, determine why.
34. Let
A =
1 0 32 3 41 0 2
.
Find A−1 if possible. If A−1 does not exist, determine why.
35. Let
A =
1 2 32 1 44 5 10
.
Find A−1 if possible. If A−1 does not exist, determine why.
36. Let
A =
1 2 0 21 1 2 02 1 −3 21 2 1 2
Find A−1 if possible. If A−1 does not exist, determine why.