Properties of Absolute Values

Introduced in Math 117

1. | -a | = | a |
2. | a b | = | a | | b |
3. | a $\pm$ b | $\le$ | a | + | b |
4. | a | < b inequivalent to -b < a < b (b > 0)
5. | a | > b is equivalent to a > b or a < -b (b > 0)
6. $\sqrt{a^2}$ = | a |