Algebra 2

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Algebra 2 Ch.4 Notes Page 35 P35 4-5 2x2
Matricies, Determinants, and Inverses
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Determinants of 2 x 2 Matricies
Square Matricies have the same number of Rows and
Columns (2 x 2) (3 x 3) (4 x 4) etc...
Identity Matrix I - Multiplying by Identity
Matrix is like Multiplying by 1.
A Matrix that is Multiplied by its inverse will
result in an Identity Matrix
If A is the Inverse of B, Then B is also the
Inverse of A AB BA I
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Example
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Inverses and Determinants
Determinants tell you if a Given Matrix has an
Inverse
If the Determinant is 0, there is NO Inverse
If the Determinant is Not 0, there is an
Inverse
(2 x 2) Matrix Determinant
Does this Matrix have an Inverse?
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Finding a (2 x 2) Inverse by Hand...
Det -2
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Using Inverses to Solve Problems
A
B
A-1A X A-1B X A-1B
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Graphing Calculator
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HW 33 4-5 P203 1,4-6,14-18,22,23,25,47 See
Example on P202-203 for 25 Please put your name
and class period at the top of the homework.
Also include the homework number.