Absolute Value Equations

Hey guys, it's Brianna here.

I kinda sorta forgot to write the blog yesterday so I am making up for it today.

When an absolute value is put on a number line, it is demonstrated as the distance from zero. On the number line below, both 3 and -3 are an equal distance from zero ( 3 units away). Therefore, the absolute value of both 3 and -3 is 3.

When we graph the function of an absolute value, we use the same method as when we graphed quadratic functions, we just have to account for the absolute value.

*You have to think of it as two separate equations.

Example 1: Graph the following function.

x	-2	-1	0	1	2
|x| (y)	2	1	0	1	2

When you make your table of values, you pick an x value and plug it into the formula. Say you picked -2 to be your x value.

The answer is two because the rule is an absolute value can never be negative. If we take a closer look at this graph and compare it to one of our old basic functions, it makes more sense.

The only difference between this function and the other one is that the left side of the function has been reflected to the other side of the axis. This is because the absolute value made all of the negative y values positive. See?

It's easy!

Anyways, the only worksheet we got was the "Graphing Absolute Value Equations" and if you finished that in class, then you have no pre-cal homework.