Using Grapher to graph a line segment ?

I'm trying to use the Grapher application in the utilities folder to graph line segments in an Algebra I course I'm teaching. Yes, I've checked the threads and I've copied a sample post below. Where do I enter rules? I also don't see the pop up window that the user is referring to below.

Any help would be greatly appreciated.

Thanks!!!







When all else fails, read the manual or, in this case, the Help file.

Entering a piecewise defined function

A piecewise equation has more than one formula. You need to enter each formula and the condition under which it should be used.
Choose Equation > New Equation.
Choose Condition from the pop-up menu next to the Equation field.
Enter the number of conditions in the equation.
Enter the conditions and expressions in the template.
Make sure the conditions are either all on the left or all on the right. If the last entry has no condition, that expression is used if none of the other conditions apply.

You can also enter a piecewise function with this format:

y = condition ? expression1 : expression2

or

y = condition : expression1 : expression2

In these examples, expression1 is used if the condition is true. Otherwise, expression2 is used. You can leave out expression2 if it's not needed.

See also
Creating graphs