Cool math fractal

math image

math image

pre-algebra help lessonsalgebra help lessonsprecalculus / calculus help lessonsmath anxiety survival guidegeometry math artmath and jigsaw puzzlesCoolmath booksother math stuff
math help lessonsmath practice problemsmath gamesmath dictionarygeometry trigonometry reference area
teacher's areaparent's areaCoolmath 4 kidsSpike's Game ZoneFinance FREAKTotally Stressed OutScience Monster

Coolmath Algebra
Matrices Lesson 6 - Inverse Matrices (page 3 of 9)
---- This algebra lesson explains how to find the inverse of a matrix

math image

Now available:  Coolmath Algebra books!  Part 1, Part 2 and Part 3 covering the Algebra you need from Algebra 1 through Precalculus Algebra (Beginning Algebra through College Algebra)

other Coolmath Books:  Coolmath Precalculus Review (the math you really need to survive Calculus 1) and Math Survival Guide (How to conquer math and deal with math anxiety)

line
Graphing Calculator Scientific Calculator << a new window will open for these
line

If we have a matrix

A = [ row 1: 2 , 3  row 2: -4 , -5 ]

We can't write 1 / A -- a result would require division.

So...  Can we find  A^( -1 )?

We sure can!  It's called an inverse matrix.  Here's how you find it:

Let's start with this matrix

A = [ row 1: 2 , 3  row 2: -4 , -5 ]

 

This is going to work a lot like Gaussian elimination.  (If you've ever seen that before.)

We make a big double matrix

[ row 1: 2 , 3  row 2: -4 , -5  |  row 1: 1 , 0   row 2: 0 , 1 ]
A on this side...                     the identity on this side.

 

The goal is to use row operations (like you did with Gaussian elimination) to...

[ row 1: 2 , 3  row 2: -4 , -5  |  row 1: 1 , 0  row 2: 0 , 1 ] ... turn the left half into I ... and, in the process, the right half with turn into A^( -1 )

Continued on the next page

 The printing and distribution and/or downloading of these lessons is strictly prohibited.

line
Graphing Calculator Scientific Calculator << a new window will open for these
line

.....:::::::::::::::  HELP SUPPORT COOLMATH  :::::::::::::::.....
:::::::  link to us   :::::::   advertise with us  :::::::  why we have ads  :::::::

Thanks for visiting Coolmath.com
© 1997-2010 Coolmath.com, Inc.