1. 4.3 The Inverse of a Matrix Warm-up (IN)
Learning Objective: to find and use the inverse and determinant of a matrix.
Warm-up (IN)
Find the multiplicative inverse of each number.
Find each product.

2. Notes The Identity Property of Multiplication - 1 is the identity
Learning Objective: to find and use the inverse and determinant of a matrix.
Notes
The Identity Property of Multiplication -
1 is the identity
(what you multiply by to get itself)
Identity of a square matrix -
Called I
4x4
2x2
3x3
If you multiply a matrix by its inverse, you get I

3. Ex 1 – Determine whether A and B are inverses of each other
Learning Objective: to find and use the inverse and determinant of a matrix.
Ex 1 – Determine whether A and B are inverses of each other
Yes they are inverses!

4. Not all matrices have an inverse…
Learning Objective: to find and use the inverse and determinant of a matrix.
Not all matrices have an inverse…
To tell if it does, find the determinant.
Then there is an inverse…
Then there is an inverse…
Ex 2 – find the determinant of the matrix and tell if it has an inverse
there is an inverse…

5. Use Calculator to find inverses!
Learning Objective: to find and use the inverse and determinant of a matrix.
there is no inverse…
Use Calculator to find inverses!

6. Out – Explain one way in which determinants can be used.
Summary – I think I understand…
HW – p. 239 #10-23
p. 241 #56-63 odd