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
dividing fractions (1)
flip on and multiply straight across
*no need for common denominator
negative base w/exponent (1)
negative stays
*in parenthesis, negative is multiplied
order of ops (1)
- parenthesis/groups
- exponents
- multiply/divide
- add/subtract
negative exponents (2)
flip to below fraction
x^-4 = x^-4/1 = 1/x^4
FOIL method (2)
First, Outer, Inner, Last
factoring polynomials by grouping (2)
1 identify 2 group 3 factor 4 identify 5 factor again
factoring trinomial a not equal to 1 (2)
ax^2+bx+c
- a*c
- find 2 numbers that multiply for that value and add for b
- rewrite b with these values
- group
- simplify and regroup
long division with polynomials (2)
*insert coefficient 0 where needed (0x)
1 divide by first item under by first item over
2 multiply first answer by items over
3 subtract and carry down
4 do again until done
5 item under is remainder
6 answer above times items over plus remainder equals polynomial
factoring binomials with 2 squares (ch2)
a^2-b^2 = (a+b)(a-b)