inverse matrices

**waterboy** · December 19th 2008, 10:36 AM

Show that the following matrices are inverse of each other

1 2
4 6

-3 1
2 -1/2

**masters** · December 19th 2008, 10:41 AM

Originally Posted by waterboy

Show that the following matrices are inverse of each other

1 2
4 6

-3 1
2 -1/2

One must assume that you know how to multiply matrices. If a matrix is the inverse of another matrix then their product will be the identity matrix.

$AB=BA=\left[\begin{array}{cc}1 & 0 \\ 0 & 1 \end {array}\right]$

Multiply them and see what happens.

**Plato** · December 19th 2008, 10:43 AM

Given $X = \left[ {\begin{array}{rr} 1 & 2 \\ 4 & 6 \\ \end{array} } \right]\,\& \,Y = \left[ {\begin{array}{rr} { - 3} & 1 \\ 2 & { - 1/2} \\ \end{array} } \right]$

You must show that $XY = YX = \left[ {\begin{array}{cc} 1 & 0 \\ 0 & 1 \\ \end{array} } \right]$

Thread: inverse matrices

LinkBack

Thread Tools

Display