Unit 8 Review Matrices

any matrix multiplied by the identity is then equal to...

• it's inverse

• itself

• can't determine without the matrix

• the identity

any matrix multiplied by its inverse is then equal to...

• it's inverse

• itself

• can't determine without the matrix

• the identity

Which is the formula for the multiplicative inverse

• 1 d -b

  ad-bc -c a  

• -a -b

  -c d

What is the inverse of A?

• 
• 
• 
• 

rewrite as a system of equations

Solve the matrix equation by finding the inverse of matrix A and multiplying it to both sides

•   x=3 , y=1

•   x=-3 , y=1  

•     x=1 , y=-3

the ADDITIVE INVERSE of ANY matrix is exactly the same except...

• the signs are switched

• every number becomes positive

• all the numbers are zero

the multiplicative identity is a matrix with

• ALL ZEROS

• 1's on the diaganol and zeros everywhere else

• ALL ONES

the additive identity is a matrix with

• ALL ZEROS

• 1's on the diaganol and zeros everywhere else

• ALL ONES

If the matrices can be multiplied, what dimension is the product? If not, write undefined.

• ( 2 x 2 )

• ( 6 x 2)

• ( 2 x 6 ) )

• ( 3 x 2 )