It is often said that mathematics is the language of science. If this is true, then the language of mathematics is numbers. The earliest use of numbers occurred 100 centuries ago in the Middle East to count, or enumerate items. Because of the evolution of number systems, we can now perform complex calculations using these and other categories of real numbers. In this section, we will explore sets of numbers, calculations with different kinds of numbers, and the use of numbers in expressions.
When one hears the word “percent,” other words come immediately to mind, words such as “century,” “cents,” or “centimeters.” A century equals 100 years. There are one hundred cents in a dollar and there are 100 centimeters in a meter. Thus, it should come as no surprise that percent means “parts per hundred.” In the world we live in we are constantly bombarded with phrases that contain the word “percent.” The sales tax in California is 8.25%. An employee is asking his boss for a 5% raise. A uni
If we carefully placed more rocks of equal weight on both sides of this formation, it would still balance. Similarly, the expressions in an equation remain balanced when we add the same quantity to both sides of the equation. In this section, we will solve equations, remembering that what we do to one side of the equation, we must also do to the other side.
René Descartes (1596-1650) was a French philosopher and mathematician. As a philosopher, he is famous for the saying “Cogito ergo sum” (“I think, therefore I am”), and his writings led many to consider him the Father of Modern Philosophy. Even today, a number of his writings are standard faire in university philosophy departments. However, it is Descartes’ work in mathematics that form the basis for this chapter, particularly his invention of the Cartesian Coordinate System which bears his name