= 
equal to 

infinity 

not equal to 
b^{n} 
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} 