A proof by contradiction states the truth of a given statement by the assuming that it is false and following by finding a conclusion that is contradictory to the given proposition that is proven to be true.
Hence, the term best describes a proof in which we assume the opposite of what we want to prove is "Proof by contradiction ".
3 because Negative numbers equal less than 0. See the number line attached below. In the number line, all the negative numbers are on the left of the zero and all the positive numbers are on the right of the 0.
