Program "Linear"

Purpose: Given an equation of a line in standard form, this program can be used to determine the slope and y-intercept of the line and/or convert to slope-intercept form. Also to explore the difference between the Prompt and Input commands.

Consider the process used to solve the standard form Ax + By = C for y. Of course the first step to isolate y is to subtract Ax from both sides leaving

By = C - Ax or By = -Ax + C (by the commutative property)

Because the y is being multiplied by B, both sides of the equation must be divided by B.

or (by the distributive property)

Examining the slope-intercept form y=mx+b, it is clear to see that slope m=-A/B and y-intercept b=C/B. Now, using the input of A, B, C, let's command the calculator to find the slope and y-intercept.

Return to your program menu and right arrow to "NEW" as before and press enter. Title your program--I chose "LINEAR" since the program involves two forms of linear equations.

You can use the "Prompt" command as before to gather input from the user. Remember, press the "PRGM" key and arrow right to the "Input/Output" menu to access these commands. To become familiar with the input command, here is a demonstration. The left image uses the prompt command, and the right image uses the input command.

Obviously, the prompt command is more efficient. Because it specifies each variable automatically, there is no need to display. Also prompt can be used for multiple values (separated by a comma), while the input only takes one argument at a time. Save the input command for functions, complex numbers, matrices, and lists, as the prompt command can only be used for real numbers and expressions.

What does the slope equal? Use the values A and B to store a value for M.

What does the y-intercept equal? Use the values for C and B to store a value for I (since we already used B, and there is no lower case form, I chose I for intercept).

The TI has now computed the slope and y-intercept, and needs to display it for the user. Use the "Disp" command in the "Input/Output" menu to output your values.

Click Here for my completed program.

RETURN to Intro/Program list.