Chapter 2 dictationary: reasoning and proof

Conjecture

Unproven statement that is based on observation

Counter example

specific case for which the conjecture is false

Conditional Statement

Logical statement that has two parts a hypothesis and a conclusion

Converse

Formed by switching the hypothesis and the conclusion

If-then form

Form of conditional statement in which that “if” part is the hypothesis and “then” is the conclusion

Hypothesis

The “If” part of an statement

Conclusion

The “then,” part in a statement

Perpendicular Lines

If two lines intersect to form a right angle

Biconditional Statement

Statement that contains the phase “if and only if”

Proof

Logical argument that shows a statement is true

Two-Column Proof

Has numbered statements and corresponding reasons that show an argument in a logical order

Theorem

Is a statement that can be proven