Helps on Using TI-8x Graphing Calculators

An Example on Using the Matrix Operations

Solving a system of linear equations using rref() - reduced row echelon form.
For example, to solve the system {2x - 3y = 4, x + y = 6}, follow the steps below:
( Depending on the model, the key strokes may be slightly different.)
1. Turn the power on and Clear everything on the display.
2. [] [] [] [] [] []
  (Assume that matrix A is selected for editing.)
3. 2 [] 3 []
4. [] 2 [] [3 [] 4 []
  (Data from the first equation.)
5. [] 1 [] 1 [] 6 []
  (Data from the second equation)
6. The TI-8x display should look like this
7. [] [] [] [] (11 times) []
  (Select the matrix operation rref() )
8. [] [] []
  (Select the matrix A.)
9. [] []
10. The above system is in reduced row echelon form. The solution of the system is:
```
       x = 4.4
       y = 1.6
```
Exercise: Show that the rref of the matrix (B) of the system of linear equations
```
     x + 2y = 3
    4x + 5y = 6   is
```
- .
  The solution is then x = -1, y = 2 directly from the last column of the final matrix in reduced row echlon form.

- 9/23/04