Explanation

For:
[ a b ]
[ c d ]

Inverse exists if:
ad − bc ≠ 0

Inverse:
(1/(ad − bc))
[ d −b ]
[ −c a ]

Quiz

1. What is the determinant?

2. When does the inverse exist?

3. What happens if determinant = 0?

4. Is the inverse unique?

5. Does inverse change dimensions?

Answer Key

1. ad − bc

2. When determinant ≠ 0

3. No inverse

4. Yes

5. No