Review of Introductory Mathematics
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 +.
For any integer (n greater than one), the nth 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
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
xi indicates the sum of numbered (indexed) values. For example, if the xi are grades
for the individual students in a class, the sum of the xi (grades) for the students in the
class of N students, divided by N, gives the average grade.
An angle is a set of points consisting of two rays with a common midpoint. It is given
An expression used to indicate a fraction of the whole, such as 50% of 90 is 45. It is
given the symbol %.
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 *