Friday, December 9, 2011

What is absolute value?

Absolute value of a variable, say x, is simply whatever you put in as a number for x say -3 it becomes positive.  It looks like this |x| .  So y = |x|  .  If x is -5 then y is 5.  If x is 10 then y is 10.   If x is -20 then y is 20.  You get the idea.  You simply make sure whatever is inside the brackets comes out positive. 


Here's one more.  y = | 5x - 10|  ...  Lets say x = -1.  What is y?

| 5(-1) - 10 | = | -5 - 10 | = |-15| = 15

Further discussion....

If you had a number line - 10 to 0 and 0 to 10 and you wanted to find the distance from from 0 to -3 the distance would not be -3 its just 3 or  | 0 - 3 |  = | - 3 | = 3