Math Glossary Letter U
undulating numbers
In base 10, numbers with the form ababa

12121, 3737373
unicode
Unicode is a computing industry standard for the consistent encoding and handling of text
uniform
In the same manner
uniform distribution
Statistical distribution with constant probability

M = 1/(b - a)
unigram
n-gram of size one
union
Combine the elements of two or more sets
unit circle
A circle centered at the origin (0, 0) with a radius of 1
unit fraction
A fraction with 1 as the numerator

For fractions n/m, the unit fraction is 1/m
unit vector
A vector with a magnitude of one
units of output depreciation
Depreciation based on asset usage
unix time
The number of seconds since January 1, 1970
unknown number
Also known as a variable
unordered partitions
upper bound
Any number greater than or equal to all elements in a set.
upper quartile
The top 25% of data set values
utility
Preference for goods and services above money