Texas Instruments TI-84 - Manual (Page 225)

Chapter 10: Matrices 222
Defining a Matrix Defining a Matrix Defining a Matrix Defining a Matrix
What Is a Matrix? What Is a Matrix? What Is a Matrix? What Is a Matrix?
A matrix is a two-dimensional array. You can display, define, or edit a matrix in the matrix
editor. The TI-84 Plus has 10 matrix variables,
[A] through [J] . You can define a matrix
directly in an expression. A matrix, depending on available memory, may have up to 99
rows or columns. You can store only real numbers in TI-84 Plus matrices.
4. Press 2
Н
3
Н
3
Н to complete the first
row for X + 2Y + 3Z = 3.
5. Press 2
Н
3
Н
4
Н
3
Н to enter the
second row for 2X + 3Y + 4Z = 3.
6. Press
y 5 to return to the home screen. If
necessary, press
‘ to clear the home screen.
Press
y  ~ to display the
MATRX MATH
menu. Press
} to wrap to the end of the menu.
Select B:rref( to copy rref( to the home screen.
7. Press
y 
1 to select 1: [A] from the
MATRX NAMES menu. Press
¤ Í. The
reduced row-echelon form of the matrix is
displayed and stored in
Ans .
1X N 1Z = L3 therefore X = L3 + Z
1Y + 2Z = 3 therefore Y = 3 N 2Z