Precalculus : Absolute Value Functions

Example Questions

Example Question #1 : Absolute Value Functions

Which of the following is a point on the following function?

Explanation:

One way to approach this problem would be to plug in each answer and see what works. However, I would be a little more strategic and eliminate any options that don't make sense.

Our y value will never be negative, so eliminate any options with a negative y-value.

Try (0,0) really quick, since it's really easy

The only point that makes sense is (5,83), therefore it is the correct answer

Example Question #2 : Absolute Value Functions

Evaluate:

Explanation:

Cancel the absolute value sign by separating the function  into its positive and negative counterparts.

Evaluate the first scenario.

Evaluate the second scenario.

The correct answer is:

Example Question #1 : Absolute Value Functions

If   , then what is the value of  when  ?

-7

13

20

-13

7

13

Explanation:

We evaluate for

Since the absolute value of any number represents its magnitude from  and is therefore always positive, the final answer would be