Formulas Flashcards
1 in roman
l
2
ll
3
lll
4
IV
5
V
6
VI
10
X
L
50
C
100
D
500
M
1000
lX
9
XX
20
XXX
30
XL
40
LXX
70
A smaller number in front of a larger number means
subtraction, all else means addition
You would not put more than 1 smaller number in
front of a larger number to sutract
Only the numbers 1, 10, 100…. can be subtracted and only from
the next two higher numbers
The roman numerals I, X and C are repeated…
up to three times in succession to form the numbers
Subtraction principal: reading from left, we
add the value of each numeral unless its value is smaller than the value of the numeral to its right in which case we subtract from that number. IX subtract 1 from 10 to get 9
I can be subtracted from
V or X (5 or 10)
X can be subtracted from
L or C (50 or 100)
C can be subtracted from
D or M (500 or 1000)
Multiplication principle: A bar placed over a roman numeral to mean
1000 times the value of the Roman numerals themselves. V(with bar) = 5 x 1000 = 5000
XL(BAR) = 40 x 1000 = 4000
{}
Set - a collection of elements
A n B
Intersection (and) - whats in common - objects that belong to set A and B
A U B
Union (or) - Objects that belong to set a or b
A C B (line under C)
Subset - has fewer elements or equal to the set
A C B (no line under C)
Proper Subset - has fewer elements than the set
A C B (line through C)
Not subset - left set not a subset of right set
2^A
Power Set - all subsets of A
A = B
Equality, both sets have the same members A={3,9,14} B={3,9,14}, A=B
U
universal set - set of all possible values
N0
Natural numbers/whole numbers (with zero) 0,1,2,3,4
N1
Natural/whole numbers without zero, 1,2,3,4
Z
Integer number set - -3,-2,-1,0,1,2,3
Q
Rational number set {xlx=a/b, a,bEN} 2/6 E Q
R
Real number set {xl - infinity < x < infinity} 6.343434 E R
Formula for number of subsets in a set
2^n where n is the cardinality of the set
Cardinality
the number of elements in a mathematical set A= {1,2,3}
Finding cardinality of union of two sets
lAUCl = lAl + lCl - lANCl
Find cardinality of intersection
write it out and see what they have in common, then count how many elements
Venn diagram - n
do not shade what they have in common
