Michealmas Flashcards
Define a statment.
A statement is a sentance which is either true or flase but not both
When can the statement “A and B” be true?
When both A and B are true
When can the statement “A or B” be ture?
When either A or B or both are true
When is the statment “not A” true?
When A is false
What does “not A” stand for?
The negation of A
How do truth tables allow us to say if two statments are the equivalent?
If the outputs from the truth tables are the same
What are the name of the four laws to do with sets and statments?
- ) Law of commutativity
- ) Law of associativity
- ) Law of distributivity
- ) De Morgan’s Law
What is the law of commutativity to do with statements?
What is the law of associativity to do with statements?
What is the law of distributivity to do with statements?
What is de morgan’s law to do with statements?
Define a set.
A set is a well defined unordered collection of elements where each element is contained only once
What does X ∪ Y stand for and mean?
Union - The set of all elements in at least one of X and Y
What does X ∩ Y stand for and mean?
Intersection - The set of all elements contained in both X and Y
What does X \ Y stand for and mean?
Difference - The set of all elements contained in X but not in Y
What does Y ⊂ X stand for and mean?
Subset - The elements of Y are also elements of X
What does Yc for Y ⊂ X stand for and mean?
Compliment - The set of elements of X which are not in Y
What is the law of commutativity to do with sets?
What is the law of associativity to do with sets?
What is the law of distributivity to do with sets?
What is de morgan’s law to do with sets?
How do you prove two sets are equal?
We prove every element of one set is also an element of the other set
Give three main equivalence between the sets and statements.
Prove de morgan’s first law.
What four properties to the order realtions: <, >, ≤, ≥ satisfy?
- ) Trichotomy
- ) Adition law
- ) Multiplication law
- ) Transitivity
What is the trichotomy property that the order relations: <, >, ≥, ≤ satisfy?
Either x < y, x=y or x >y
What is the addition law that the order relations: <, >, ≥, ≤ satisfy?
If x < y and a ∈ ℝ, then x + a < y + a
What is the multiplciation law that the order relations: <, >, ≥, ≤ satisfy?
If x < y and c > 0, then cx < cy
If x > y and c < 0, then cx > cy
What is the transitivity property that the order relations: <, >, ≥, ≤ satisfy?
If x < y and y < z, then x < z
Prove that if x < y and a < b then x + a < y + b.
What four rules are important when considering inequalities involing absolute values?