Graphing absolute values?

Question

Anyone know a good website or can explain to me how to do this?

Answer 1

Set the equation up so that you have different equations for different values. For example:

y = |x^2 - 4|

When x is less than 2 or -2, then x^2 - 4 is a negative number - at which point the absolute value sign converts it to a positive number. Therefore, you're graphing 3 partial functions:
y = x^2 - 4 for x >=2
y = -(x^2 - 4) for -2 < x < 2
y = x^2 - 4 for x <= -2

Answer 2

http://www.purplemath.com/modules/graphabs.htm