Truth TableDate: 04/14/99 at 07:23:22 From: Sherri Pretorius Subject: Discrete Mathematics - Baby set theory I need help desperately with this one - I just keep getting it wrong. Prove that (X(an upside down U)Y)' = X' u Y' without using a Venn diagram. Thanks, Sherri Date: 04/14/99 at 14:11:02 From: Doctor Anthony Subject: Re: Discrete Mathematics - Baby set theory You can use a truth table. (x and y) means INTERSECTION and you multiply (x or y) means UNION and you add x y x' y' (x and y) (x and y)' (x' or y') ------------------------------------------------------- 0 0 1 1 0 1 1 0 1 1 0 0 1 1 1 0 0 1 0 1 1 1 1 0 0 1 0 0 ------------------------------------------------------- Comparing the last two columns we see that the two expressions are identical. It follows that (x and y)' = x' or y' - Doctor Anthony, The Math Forum http://mathforum.org/dr.math/ |
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