This chapter reviews the terminology and associated symbols used in mathematics.

EO 1.1 IDENTIFY the following basic symbols and definitions.

In order to understand and communicate in mathematical terms and to lay the foundation for the concepts and principles presented in this material, certain terms and expressions must be defined. This section covers basic definitions used in mathematics. Once understood, such knowledge should provide the foundation from which the principles of mathematics can be presented. By no means are the terms here all inclusive; they are representative of those found within the nuclear field.

Equals

An expression indicating values which are identical in mathematical value or logical denotation. It is given the symbol =.

Is Not Equal to

An expression indicating values which are not identical in mathematical value or logical denotation. It is given the symbol or ><, >< (computer).

Is defined as

A mathematical expression for defining a symbol or variable in mathematics. It is usually given the symbol .

Plus or Minus

While plus (+) and minus (-) are used individually to indicate addition and subtraction, this form is used to denote a control band, or tolerance band, or error band, such as 100 + 5 psig. It is given the symbol +.

n^th root

For any integer (n greater than one), the n^th root () of a is defined as follows:

= b if, and only if, bⁿ = a. The number n, in , is called the index of the root. The nth root of a number (a) is a number (b) which has the property that the product of n values of b is a. For example, the third (or cube) root of 8 is 2, because 2x2x2 equals 8.

Absolute Value of a

This expression represents the magnitude of a variable without regard to its sign. It signifies the distance from zero on a number line. That is, the absolute value of -6 is 6 because -6 is 6 units from zero. Likewise, the absolute value of +6 is 6 because it, too, is 6 units from zero. It is given the symbol where A is any number or variable.

Sum of N values N

indicates the sum of numbered (indexed) values. For example, if the x_i are grades for the individual students in a class, the sum of the x_i (grades) for the students in the class of N students, divided by N, gives the average grade.

Angle

An angle is a set of points consisting of two rays with a common midpoint. It is given the symbol .

Percent

An expression used to indicate a fraction of the whole, such as 50% of 90 is 45. It is given the symbol %.

Multiplied by

A mathematical operation that, at its simplest, is an abbreviated process of adding an integer to itself a specified number of times. It is given the symbols x, ^. , or * (computer).

Divided by

A mathematical process that subjects a number to the operation of finding out how many times it contains another number. It is given the symbol or /.

Greater than or equal to

it is given the symbol >, and denotes one quantity is equal to or larger than another.

Less than or equal to

It is given the symbol <, and denotes one quantity is equal to or smaller than another.

Infinity

A mathematical expression meaning very large in magnitude or distance. It is so large that it cannot be measured. It is given the symbol .

Is Proportional to

The statement that a is proportionl to b (a a b) means that a = (some constant) x b. For example, the dollars you earn in a week (straight rate) are proportional to the hours you work, with the constant being the dollars per hour you earn.

Approximately Equal to

An expression indicating a value which is not exact, but rather close to the value. It is given the symbol .

Perpendicular to

This expression means that two objects are at right angles (form a 90-degree angle) to each other. It is given the symbol .

Parallel to

Two lines extending in the same direction which are everywhere equidistant and not meeting. It is given the symbol || .

Summary

The important information from this chapter is summarized below.

Terminology Summary

This chapter reviewed the terminology needed in the application and study of mathematics.