《托马斯微积分》 第11版 （附带习题答案）_部分1.pdf

C h a p t e r 1 PRELIMINARIES OVERVIEW This chapter reviews the basic ideas you need to start calculus. The topics in- clude the real number system, Cartesian coordinates in the plane, straight lines, parabolas, circles, functions, and trigonometry. We also discuss the use of graphing calculators and computer graphing software. 1.1 Real Numbers and the Real Line This section reviews real numbers, inequalities, intervals, and absolute values. Real Numbers Much of calculus is based on properties of the real number system. Real numbers are numbers that can be expressed as decimals, such as 3 - = - 0.75000 Á 4 1 = 0.33333 Á 3 22 = 1.4142 Á The dots Á in each case indicate that the sequence of decimal digits goes on forever. Every conceivable decimal expansion represents a real number, although some numbers have two representations. For instance, the infinite decimals .999 Á and 1.0