Calculator Commands for Linear Algebra
Graphing calculators are wonderful tools for helping you solve linear algebra processes; they allow you to drain battery power rather than brain power. Since there is a wide variety of graphing calculators out there, the following are general instructions for help with linear algebra that apply to most graphing calculators:
To solve systems of equations by graphing:

1. Write each equation in y = mx + b form.

2. Insert equations in the ymenu.

3. Graph the lines.

4. Use the Intersection tool to get the answer.
To add or subtract matrices:

1. Insert the elements into the matrices A and B.

2. With a new screen, press [A] + [B] or [A] – [B], and press Enter.
To multiply by a scalar:

1. Insert the elements into the matrix A.

2. With a new screen, press the scalar and multiply: k * [A], and press Enter.
To multiply two matrices together:

1. Insert the elements into the matrices A and B.

2. With a new screen, press [A] * [B], and press Enter.
To switch rows:

1. Insert the elements into a matrix.

2. Use row swap: rowSwap ([matrix name], first row, second row), and press Enter.
To add two rows together:

1. Insert the elements into a matrix.

2. Use row addition: “row +”, ([matrix name], row to be added to target row, target row), and press Enter.
To add the multiple of one row to another:

1. Insert the elements into a matrix.

2. Use row sum–of–multiple: “*row +”, (multiplier, [matrix name], row being multiplied, target row having multiple added to it), and press Enter.
To multiply a row by a scalar:

1. Insert the elements into a matrix.

2. Use row multiple: “*row” (multiplier, [matrix name], row), and press Enter.
To create an echelon form:

1. Insert the elements into a matrix.

2. Use row–echelon form: ref ([matrix name]) or reduced rowechelon form: rref ([matrix name]), and press Enter.
To raise a matrix to a power:

1. Insert the elements into a matrix.

2. Use the caret operation with power, p: [matrix name] ^ p, and press Enter.
To find inverses:

1. Insert the elements into a matrix.

2. Use the reciprocal operation, x^{−1}: [matrix name]^{−1}, and press Enter.
To solve systems of linear equations:
(This only works when the system has a single solution; it fails when the matrix A is singular.)

1. Write each equation with the variables in the same order and the constant on the other side of the equation sign.

2. Create a matrix A, whose elements are the coefficients of the variables.

3. Create a matrix B, whose elements are the constants.

4. Press, A^{−1} * B, and press Enter.
The resulting vector has the values of the variables, in order.