# Chapter 2 Vocab

## 18 terms

### conjecture

An unproven statement that is based on observations.

### inductive reasoning

A process that includes looking for patterns and making conjectures.

### counterexample

A specific case that shows a conjecture is false.

### conditional statement

A type of logical statement that has two parts, a hypothesis and a conclusion.

### converse

The statement formed by exchanging the hypothesis and conclusion of a conditional statement.

### inverse

The statement formed by negating the hypothesis and conclusion of a conditional statement.

### contrapositive

The equivalent statement formed by negating the hypothesis and conclusion of a conditional statement.

### if-then form

The form of a conditional statement that uses the words "if" and "then." The "if" part contains the hypothesis and the "then" part contains the conclusion.

### hypothesis

The "if" part of a conditional statement.

### conclusion

The "then" part of a conditional statement.

### negation

The opposite of a statement.

### equivalent statements

Two statements that are both true or both false.

### perpendicular lines

Two lines that intersect to form a right angle.

### biconditional statement

A statement that contains the phrase "if and only if."

### deductive reasoning

A process that uses facts, definitions, accepted properties, and the laws of logic to form a logical argument.

### proof

A logical argument that shows a statement is true.

### two-column proof

A type of proof written as numbered statements and corresponding reasons that show an argument in a logical order.

### theorem

A true statement that follows as a result of other true statements.