1 / 7

# Identity and Inverse Matrices - PowerPoint PPT Presentation

Identity and Inverse Matrices. Key Topics. Identity matrix : a square matrix, multiplied with another matrix doesn’t change the other matrix (just like 1 is the multiplicative identity of real numbers). Identity Matrix in Action.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## PowerPoint Slideshow about 'Identity and Inverse Matrices' - zora

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

### Identity and Inverse Matrices

• Identity matrix: a square matrix, multiplied with another matrix doesn’t change the other matrix (just like 1 is the multiplicative identity of real numbers)

Notice: These two matrices are the same. Multiplying by the identity matrix changed nothing

Notice: These two matrices are the same. Multiplying by the identity matrix changed nothing

• You might be wondering: why do I tell you about the identity matrix ?? If it doesn’t do anything, why do we need to know what it is ??

• Inverses: two nXn matrices are inverses of each other if their product is the identity matrix

• Determine whether the following pairs of matrices are inverses of one another:

• To find the inverse of a 2X2 matrix, use the following method:

Rearranged matrix

Inverse of Determinant

If determinant is 0 there is no inverse!!

Basically this tells us to calculate the determinant, then multiply it’s inverse by the rearranged matrix having a and d switch places and b and c as the opposite values

A-1 is the notation used to represent the inverse of matrix A

• Find the inverse matrix for the following matrices:

N/A