Truth Tables

Objectives:
  • Construct a truth table for a given symbolic expression.
  • Determine if two given statements are equivalent using truth tables.
  • Use De Morgan’s Laws to write a statement equivalent to a given statement.



Vocabulary:
  • truth table
  • equivalent expressions
  • De Morgan’s Laws
Negation
p
~p
T

F


Conjunction
p
q
p and q
T
T

T
F

F
T

F
F


Disjunction
p
q
p or q
T
T

T
F

F
T

F
F


Conditional
p
q
p implies q
T
T

T
F

F
T

F
F


Click here for a video explaining how to fill in the truth tables.

Possible Classroom Examples:

p
~p
p or not p







p q
p and q
~q
p and q implies not q





















If the lyrics are not controversial, then performance is not banned.
p:
q:
symbolic form:
p
q  
 
      





















The country singer is in trouble if he is elected.
p:
q:
symbolic form:
p
q  
 
      





















If he does not go to jail, he is innocent or has an alibi.
p:
q:
r:

symbolic form:
p
q r
 





      

























































































p
q
  
  
  





















p
q
  
  
  





















The streets are wet or it is not raining.

If it is raining, then the streets are wet.
p:
q:

symbolic form:
symbolic form:
p
q
 
 
 






















p
q
 
 
 






















© 2007 Elizabeth E. K. Jones and the ASU Department of Mathematics and Statistics - All rights reserved.