Truth Tables (2.4)

Question 1

Truth Table for an AND gate

Answer 1

• Call the two inputs A and B
• Call the output C
• If A is False AND B is False then C is False
• False + True = False
• True + False = False
• True + True = True

Question 2

Tip for doing a multi-gate truth table

Answer 2

• When completing a truth table it is easy to forget what you have done or repeat a combination.
• The best thing to do is pick one of the gates to alternate the different combinations with.

Question 3

Rewrite S = (P AND Q) OR (NOT R) using symbols

Answer 3

• S = (P /\ Q) \/ (¬ R)

Question 4

Rewrite R = (NOT Q) OR P using symbols

Answer 4

• R = (¬ Q) \/ P