Deductive Reasoning : reasoning in which the conclusion is based on statements that are
accepted as true.
http://www.edcollins.com/logic/index.html
Two Column Proofs: these are tools a mathematician uses to communicate his thoughts
to other people. A two column proof is used to clearly explain how a mathematical or
logical result is obtained.
1. Solve the equation
work.
Statements
Title: Apr 21­8:39 AM (1 of 9)
3(x + 4) - 5 = x + 13. Use a two column proof to explain your
Reasons
Even Integers
Title: Apr 21­9:50 AM (2 of 9)
Odd Integers
Prove that the sum of two odd integers is an even integer.
Statements
Title: Apr 21­9:52 AM (3 of 9)
Reasons
Prove that the square of an odd number is always odd.
Statements
Title: Apr 21­9:53 AM (4 of 9)
Reasons
Conditions for Congruent Triangles
Title: Apr 21­9:55 AM (5 of 9)
Title: Apr 21­10:00 AM (6 of 9)
Title: Apr 21­10:02 AM (7 of 9)
Refexive Property : this word is used as the reason when we want to say that a
number is equal to itself.
Title: Apr 21­10:04 AM (8 of 9)
Homework: Set up two column proofs for each of these statements.
1. page 410: 3,6,9
2. The solution to 2(5x + 1) + 7 = 3(x - 2) + 43 is x = 4.
3. The solutions to
are x = 4 and x = -2
4. The product of an even number with an odd number is even.
5. The square of an even number plus and odd number is always odd.
Title: Apr 21­10:10 AM (9 of 9)