Question

how do you find the multiplicative inverse in a matrix ??

Answer 1

http://www.mathwords.com/i/inverse_of_a_matrix.htm

Answer 2

dividing adjoint of it by it's determinant. and it implies that the matix with non zero determinant only has multiplicative inverse

Answer 3

here's the matrix :


7,1,2
-5,0,-1
2,1,3

Answer 4

no quick snappy method, have to grind it until you find it

Answer 5

how do i start?

Answer 6

choose 2x2 matrix first

Answer 7

The link I posted gives you the formula to find the inverse of the matrix (both 2x2 and 3x3). There is a link at the bottom that will give you the formula for determining the determinant of the 3x3 matrix.

Answer 8

Also, make sure you check your work.

Answer 9

@Bailey.Nae do you know gaussian elimination?

Answer 10

noo

Answer 11

do you know how to find the determinant of this matrix?

Answer 12

noo

Answer 13

then you are very far away from being able to find the inverse of this matrix
learn gaussian elimination
then row reduction
then determinants and adjoints

after that, then come back and ask about finding the inverse of a 3x3 matrix

Answer 14

unless of course you want to cheat and use wolfram alpha
http://www.wolframalpha.com/input/?i=inverse+%5B7%2C1%2C2%5D%2C%5B+-5%2C0%2C-1%5D%2C%5B+2%2C1%2C3+%5D

Answer 15

if you want to learn how it is done, read through this entire course

http://tutorial.math.lamar.edu/Classes/LinAlg/LinAlg.aspx

or at least half of it