3. Validating the statements involving the connecting words and statements

Validating the statements involving the connecting words and statements:

METHODS OF PROOF

Mathematical proofs are deductive in nature. A mathematical argument consists of a set of propositions (called hypotheses) and a set of conclusions. It is called logically valid if the conclusions are true. Otherwise called logically invalid.

There are several methods to show an argument is valid which are:

1. Principle of syllogism.
2. Principle of reduction absurdum.
3. Law of contrapositive.
4. Principle of mathematical induction.

OR

Validating Statements

The following methods are used to check the validity of statements:

(i) direct method

(ii) contrapositive method

(iii) method of contradiction

(iv) using a counter example.