Download Deductive Reasoning

WARM UP
If possible, write the bi-conditional form of
the statement below:
Palm trees grow in warm climates
ANNOUNCEMENTS
• Retention Quiz Friday
• Half old material, half new material
• Homework and Warm ups due Friday
WHAT CAN WE CONCLUDE???
• Sherlock Holmes knows that
whoever was in the kitchen
stole the tomatoes
• Sherlock Holmes discovers that
Mrs. Hudson was in the kitchen
• What can he conclude?
DEDUCTIVE REASONING
• The process of using logic to
get from what you know is
true to new conclusions
• If the statements are true
(what you know) what you
conclude will also be true
TYPE ONE
• If Ms. Keller is hungry then she
is grumpy
• Ms. Keller is hungry
• What can we conclude???
LAW OF DETACHMENT
If a conditional statement its true, and its
hypothesis is true, then its conclusion will be
true as well.
Symbolic form:
If p→q is a true statement and p is true then q
is true
**→ means if then statement
TYPE TWO
• If it rains the flowers will grow
• If the flowers grow Ms. Keller will be happy
THEREFORE
• If it rains Ms. Keller will be __________
WHAT DID WE DO???
What do you notice about the first two
conditional statements?
LAW OF SYLLOGISM
Allows you to state one conclusion
from 2 true conditional statements
when the conclusion from one
statement is the hypothesis from
the other statement.
Symbolic Form:
If p→q and q→r are true
statements, then p→r is a true
statement
**→ means if then statement
HOMEWORK
Pg: 62-63 #’s 1-4 & 6-11