2. Section 2.5 If-Then Statements and Deductive Reasoning pg.82

3. Definition If/Then Statement - a rule that says if one thing is true, then another thing is also true. If you don’t study, Then you will fail. Hypothesis - If part. The statement that must be true for the rule to apply. Conclusion - The part that can be assumed if the Hypothesis is true.

4. Definition If/Then Statement - a rule that says if one thing is true, then another thing is also true. If the team wins the semi-final, Then the team will play in the championship. Hypothesis - If part. The statement that must be true for the rule to apply. Conclusion - The part that can be assumed if the Hypothesis is true.

5. If/Then Statement Example If I pass the driving test, then I will get my driver’s license. Hypothesis - Conclusion - If I pass the driving test, then I will get my driver’s license.

6. If p  q and p is true then q is true. If the hypothesis is true, then the conclusion can be assumed to be true. or

7. Tips about Laws of Logic Law of Detachment This law involves one(1) if, then statement and another simple statement which produces another simple statement.

8. If the Schurz football team scores 4 touchdowns, then the football team will win. The bulldogs scores 7 touchdowns against Lane Tech. Win vs. Lane No Conclusion The bulldogs picks off 3 passes against Mather. Tavaris scores 3 touchdowns and Angel scores 2 against Von Steuben. Win vs. Dixie The team pummels Lake View. No Conclusion?

9. If p  q and q  r, are true, then p  r is also true. Several if/then statements can be hooked together. If the first hypothesis is true, then the last conclusion can be assumed to be true.

10. If Mr Patel sees your cell phone, Then he will take it from you. If Mr Patel takes your phone, Then he will call his sister in NYC. If Mr. Patel calls his sister in NYC, Then He will listen to her for over an hour. If He listens to her for over an hour, Then your roaming charges will be outrageous. Conclusion?

11. If Mr Patel sees your cell phone {p}, Then he will take it from you {q}. If Mr Patel takes your phone, {q} Then he will call his sister in NYC {n}. If Mr. Patel calls his sister in NYC, {n} Then He will listen to her for over an hour.{u} If He listens to her for over an hour, {u} Then your roaming charges will be outrageous. {r} Conclusion?

12. Tell your neighbor everything you can about this picture. 1 2 3 4 5 6 7 8

13. More Examples Law of Detachment – If the dog barks, then it will wake the baby. Hypothesis: The dog barks. Conclusion: ?

14. More Examples Law of Syllogism - If the dog barks, then it will wake the baby. - If the baby wakes, then mom will be mad. Conclusion?  If mad gets mad, then you can’t go to the party.

15. Class Work Practice Rewrite statement as “if, then” statement 1.Every game on my computer is fun to play.  If a game is on my computer, then it is fun to play

16. Class Work Practice Rewrite statement as “if, then” statement 2. I will buy the CD if it costs less than $15  If the CD costs less that $15, then I will buy it.

17. Class Work Practice Rewrite statement as “if, then” statement 3. All teachers at Schurz High School have taught for at least 5 years.  If a teacher works at Schurz, then he or she has taught for at least 5 years.

18. Class Work Practice Rewrite statement as “if, then” statement 4. An angle is obtuse if its measure is 170 degrees  If the measure of an angle is 170, then the angle is obtuse.

19. Class Work Practice What can you conclude from the given true statements 6. If you study at least two hours for the test, then you will pass the test. You study three hours for the test.  You will pass the test.

20. Class Work Practice What can you conclude from the given true statements 6. If x has a value of 7, then 2x – 3 has a value of 11. The value of x is 7.  2x-3 has a value of 11.

21. Homework pg.85 #7-15