Sometimes we need to show that a claim is false. This can be done by finding a counterexample. Consider any claim of the form: . To show that the claim is false, we need to find a value of
for which
is true and
is false.
That is, we need to prove the negation of the above claim: . Finding any
that supports the negation of the original claim is sufficient to disprove it. Continue reading “Disproof by Counter Example”