Absolute Value
1. Problem: Evaluate the absolute value function $|x|$ at $x=-3,0,3,100,-100$ and explain the piecewise definition and graph.
2. Recall the definition of absolute value.
$$|x|=\begin{cases} x & \text{if } x>0 \\ 0 & \text{if } x=0 \\ -x & \text{if } x<0 \end{cases}$$
3. Evaluate each given value.
For $x=3$ since $3>0$ we use the first branch and get $|3|=3$.
For $x=-3$ since $-3<0$ we use the third branch and get $|-3|=-(-3)=3$.
For $x=0$ since $0=0$ we use the second branch and get $|0|=0$.
For $x=100$ since $100>0$ we use the first branch and get $|100|=100$.
For $x=-100$ since $-100<0$ we use the third branch and get $|-100|=-(-100)=100$.
4. Graph explanation.
The graph of $y=|x|$ is a V-shaped curve with its vertex at $ (0,0) $ and symmetric about the $y$-axis.
It has a global minimum at $y=0$ attained at $x=0$ and no maximum.
Final answers: $|3|=3$, $|-3|=3$, $|0|=0$, $|100|=100$, $|-100|=100$.