2.4 Deductive Reasoning

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2.4 Deductive Reasoning
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Review

• Cond
• Conv
• Inv
• Contra

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2 Types of Reasoning
Deductive based on _________________________ to
reach a logical concl

• Inductive
• Based on __________ to get a conj

2 Types of Deductive Reasoning
Law of Detachment Law of
Syllogism(detach) (syll)
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Hints

• To see if its law of detach or law of syll, do
  this
• See if its valid
• Set it up (assign p, q, r)
• Example Give a valid concl (if poss) the law.
• If its snowing ? its cold outside.
• Its not snowing.

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Examples Give a valid concl (if poss) the law.

• A. If you drink milk, your body gets calcium.
• If your body gets calcium, you will have strong
  bones teeth.
• B. If you study, you should pass the test.
• Frank did study.
• C. Vertical angles are congruent.
• ltABC ltDBE are vertical angles.

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Assignment

• 2.4 p. 85 (12-30 all, 40-58 even)