natural numbers N integers Z rational numbers Q

數系 • • • 自然數 (natural numbers) N → 整數 (integers) Z →有理數(rational numbers) Q →實數 (real numbers) R →複數 (complex numbers) C 微積分只需用到實數

The Real Numbers The real numbers can be ordered and represented in order on a number line 0 -1. 87 4. 55 x -3 -2 -1 0 1 2 3 4

Inequalities, graphs, and notations Inequality Graph Interval ( ] 3 7 ( 5 ] ) or ( means not included in the solution ] or [ means included in the solution

Absolute Value To evaluate: Notice the opposite sign

Exponents n, m positive integers Definition n factors Example

Laws of Exponents Law Example