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Geometry Notes. Section 2-4. What you’ll learn. How to use the Law of Detachment How to use the Law of Syllogism. Vocabulary . Deductive reasoning Law of Detachment Law of Syllogism. Deductive Reasoning. DEFN Deductive Reasoning :
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Geometry Notes Section 2-4
What you’ll learn • How to use the Law of Detachment • How to use the Law of Syllogism
Vocabulary • Deductive reasoning • Law of Detachment • Law of Syllogism
Deductive Reasoning • DEFN Deductive Reasoning: • An argument that uses facts, rules, definitions or properties to reach a logical conclusion • Two basic forms of deductive reasoning are: • Law of Detachment • Law of Syllogism
Examples of Deductive Reasoning • First we need facts, rules, definitions or properties to work with. • Interesting Facts: • All geometry students love TAB. • KJ is a geometry student. • What is a logical conclusion based on that information? • KJ loves TAB. • Let’s build on our interesting facts. . .
Examples of Deductive Reasoning Continued • Interesting Facts: • All geometry students love TAB. • KJ is a geometry student. • Stacy is a history student. • Any new conclusions? • Why not? Nope. History student has nothing to connect to • Let’s continue building our interesting facts.
Interesting Facts: • All geometry students love TAB. • KJ is a geometry student. • Stacy is a history student. • Geometry students who love TAB have been known to steal one. • Any new conclusions? • What? • Let’s continue building our interesting facts.
Interesting Facts: • All geometry students love TAB. • KJ is a geometry student. • Stacy is a history student. • Geometry students who love TAB have been known to steal one. • KJ is a history student too . • Any new conclusions? • Why not? • Let’s continue building our interesting facts.
Interesting Facts: • All geometry students love TAB. • KJ is a geometry student. • Stacy is a history student. • Geometry students who love TAB have been known to steal one. • KJ is a history student too. • Students who steal TAB carry it in their bookbag. • Any new conclusions? • What is it?
Interesting Facts: • All geometry students love TAB. • KJ is a geometry student. • Stacy is a history student. • Geometry students who love TAB have been known to steal one. • KJ is a history student too. • Students who steal TAB hide it in their bookbag.
Have you learned. . . Or did we? Hey! We didn’t do these! • How to use the Law of Detachment? • How to use the Law of Syllogism? • Assignment: Worksheet 2.4
Law of Detachment • Given p→q and p as true therefore q must be true. p→q p q • What part of our argument illustrates the Law of Detachment?
Law of Syllogism • Given p→q and q →r as true therefore p→r must be true. p→q q →r p→r • What part of our argument illustrates the Law of Syllogism?