Manual Hp 48G

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HP 48GII Solving linear systems of equations using matrices

The Numeric Solver
Solving linear systems of equations
Practice solving linear systems

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HP 48GII Solving linear systems of equations using matrices
The Numeric Solver
The HP 48GII has a numeric solver that can find the solutions to many different types of problems. It is invoked by pressing theRED
shift key followed by the 7 key, or …Ï.
When pressed, the CHOOSE box below is displayed:

Figure 1

The first choice allows for the solution of an equation containing a number of unknowns. The second choice solves differential
equation problems. The third choice solves for zeroes of a polynomial. The fourth choice to solve linear systems of equations is the
one of interest here. Thefifth choice invokes the finance solver. The sixth choice begins the multiple equation solver. To select the
linear systems solver, press 4`. The 48GII displays the following screen:

Figure 2

There are three input areas on this form. The first area is labeled A: and is where the matrix containing the coefficients of the system
of linear equations are entered. The second area is labeled B:and is where the constants from the system of equations are entered.
The third area is where the values of the unknown variables X in the systems of linear equations are returned when a solution is
found. To enter the coefficients in a matrix, press !!!EDIT!! when the cursor is beside the area labeled A: and the MatrixWriter is
launched.

Figure 3

In many ways, this screen works like anyspreadsheet. Enter numbers and they will go in the highlighted cell. The menu labels at the
lower left corner of the screen, !!!GO²!! and !!GO°!, determine the direction the cursor moves after a data point has been entered, either
right to the next column or down to the next row. In this example, the selection is to move right after each data point has been
entered. This is indicated by thesquare present next to the !!!GO²!! menu label. To change the way the cursor will move, press the
menu label for the direction desired and the square in the menu label will change accordingly. If a column is too small to show the
data entered, the !!!WID²!! and !!±WID!!! menu keys may be used to expand or shrink the area displayed for each column.
Enter the first coefficient from the first equationby keying in the numbers and pressing the `key. The cursor will move to the right
into the second column where the second coefficient should be keyed with the `key pressed to accept this value. At this point,
the cursor will be in column 3. If the system of linear equations being entered has more than two unknown variables, continue
entering the data until done. Use the ˜ and š keys to moveback to the first column and enter the coefficients from the second
equation. Continue entering rows of data into the matrix until done. If at any time you notice a mistake in the data, use the arrow keys
to go back to the incorrect data value, key in the correction, press the ` key to accept the change, and then use the arrow keys to
go back to where you were. After entering a matrix, the screenwould look something like this:

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HP 48GII Solving linear systems of equations using matrices

hp calculators
HP 48GII Solving linear systems of equations using matrices

Figure 4

To accept the data as input, press the `key and the matrix will be returned to the system of linear equations solver.

Figure 5

To enter the constants for the linear equations,press the ˜key and press the menu label !!!EDIT!! above the A key. The
MatrixWriter will be brought up a second time to enter the constants. Note that the constants are entered as a column of numbers
rather than a row. Enter the numbers the same way that the coefficients were entered.

Figure 6

When the `key is pressed, the constants are returned to the linear equation system solver in the...