Alegebra Flashcards
natural numbers (1)
1,2,3,… aka counting numbers
all positive, whole numbers
whole numbers (1)
natural numbers starting at 0
integers (1)
combine negative numbers with whole number
rational number (1)
quotient of two integers
includes repeating and terminating decimals
irrational numbers (1)
cannot be expressed as quotient of two integers
includes ongoing decimals
open interval (1)
*interval - (a,b)
*set-building - {x|a<b}
hollow/open dots
closed interval (1)
*interval - [a,b]
*set-builder - {x|a<=b}
closed/filled dots
half-open intervals (1)
*interval - (a,b]
*set-builder - {x|a<=b}
hollow a, full b
open infinite intervals (1)
- interval - (a,infinity)
* set-builder - {x|x>a}
sets - union and intersection (1)
- union - elements when you COMBINE sets (U) - like a bucket
* intersection - elements common in both (Upside-down U) like “N”. Empty set is 0.
absolute value (1)
distance between number and 0
|n|
opposite (1)
x + opposite = 0
multiply fractions (1)
top and bottom straight across
*don’t need common denominator
reciprocal (1_
x * reciprocal = 1
flip fraction, keep sign
defined vs undefined (1)
a/b and a and b are real numbers and b is not 0