Midterm 1 Flashcards
What are Polyas 4 steps
- Understand the problem- read it, pick out what you know, figure out what its asking
- Devise a plan- draw diagram, look for patterns, guess & check, solve a simpler problem, work backwards, use variable
- Carry out the plan
- Look back- make sure your answer answered the question being asked, check your work, work backwards, evaluate your strategy
- come up with a related problem
Set definition
a group of objects, called elements
what does A = B mean regarding sets
the sets are the same
1-1 correspondance
each element in sat A can be matched with one, and only one element in set b
subset
every element of A is also an element of B
finite
can be counted with an end
infinite
never ends
union (U)
the set of elements that bring to A or B or Both
Intersection
the elements common to A and B
Complement
The elements of the universal set that aren’t in A
Difference of sets
the set of all elects in A that are not in B
Cartesian Product of sets
set of all ordered pairs made from elements in each
N
the number of all ordered pairs made. Multiply the total number of elements in each set by each other
Roman Numerals
I=1 V=5 X=10 L=50 C=100 D=500 M=1000 Can only subtract from 2 letters up the ladder (I,C,X) 4=IV, 9=1X, 99=XCIX, 40=XL, 90=XC, 400=CD, 900=CM
Hindu-Arabic Number system
Ours- 0,1,2,3,4,5,6,7,8,9
4 Properties of addition
- Closure property- the sum of any 2 whole numbers is a whole number
- Commutative property- a+b=b+a
- Associative property- (a+b)+c=a(b+c)
- Identify property- unique whole number such that a+0=0+a=a
Closure Property (+)
the sum of any two whole numbers is a whole number
Commutative Property (+)
a+b = b+a
Associative Property (+)
(a+b)+c = a+(b+c)
Identify Property (+)
There is a unique whole number (usually zero) such that a+0=0+a=a
Addition of whole numbers
let a and b be any whole numbers. if A and B are disjoint sets with a=n(A) and b=n(B), then a+b=n(AUB)