HP 39gII, User Manual

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202 Matrices
6. Return to Home and enter the calculation to
left-multiply the constants vector by the inverse of the
coefficients matrix.
HA
M2
S
x
–1
s
A
M1
E
The result is a vector of the solutions x = 2, y = 3 and z =
–2.
An alternative method, is to use the RREF function.
Matrix functions and commands
About functions
•
Functions can be used in any app or in Home. They
are listed in the Math menu under the Matrix
category. They can be used in mathematical
expressions—primarily in Home—as well as in
programs.
•
Functions always produce and display a result. They
do not change any stored variables, such as a matrix
variable.
•
Functions have arguments that are enclosed in
parentheses and separated by commas; for example,
CROSS
( vector1 , vector2 ). The matrix input can be
either a matrix variable name (such as
M1
) or the
actual matrix data inside brackets. For example,
CROSS(M1,[1,2])
.
About commands
Matrix commands are listed in the CMDS menu (
S
CMDS
), in the matrix category.
See the chapter titled Programming for more information
on matrix commands.
Functions differ from commands in that a function can be
used in an expression. Commands cannot be used in an
expression.