Table of Algebra Symbols
= equal to infinity
not equal to bn b to the nth power
approximately equal to The nth root of x or 
> Greater than The square root of a
Greater than or equal to i Imaginary number
< Less than a+bi Complex number
Less than or equal to plus or minus
a<x<b x is less than b and greater than a (a, b) An ordered pair; often a is associated with x and b is associated with y
x is less than and equal to b and greater than and equal to a f,g,h,y etc. Name of functions
Repeating decimal:  f(x) Notation for a function of x
LCM Least common multiple The composite of the functions f and g
LCD Least common denominator Notation for the inverse of the function f
{a,b, c,d} The set with elements a, b, c, d pi
The set of all x greater than or equal to a The nth term of a sequence
The null set or empty set Sum of n terms of a sequence
a is an element of set B Summation sign
a is not an element of set B Infinite sum of a sequence
a is a subset of set B n! The nth factorial - 
An interaction between sets A and B Common logarithm (base 10) or x=10 y
A union between sets A and B Natural logarithm (base e) or x=e y
|x| The absolute value of x Logarithm, to the base b, of x or x=b y