# Homework Help: How would I graph this in my TI-83?

1. Aug 17, 2011

### hyde2042

1. The problem statement, all variables and given/known data

|y| = 7-x

The closest I can do is y=abs(7-x), but this just gives me a straight line along the y axis. Thank you for your time.

2. Relevant equations

3. The attempt at a solution

2. Aug 18, 2011

### SammyS

Staff Emeritus
In this case x is a function of y, rather than y being a function of x.

You can either:
(1). Graph x on the vertical axis & y on the horizontal axis by switching x & y in your equation, then solve for y.

(2). Do a parametric plot: Let yt = t and xt = 7 - abs(t), because x = 7 - |y|. Have t go from -20 to 20.​

3. Aug 18, 2011

### PeterO

You could graph two lines: y = 7 - x and -y = 7 - x [better known as y = x - 7]

This would give to two intersecting lines making a large X

You only want two if the branches.

You want either the V, the inverted V [can't type it upside down] or the left hand two [>] or the right hand two [<].

You could test the original expression by chosing a known point on each of the sections, to check which two you want, if you can't think of any other way of doing it.

4. Aug 18, 2011

### hyde2042

Ah. THank you guys. I wish I thought of those methods.