Disjunction in mathematical logic.<br />Hello friends, Welcome to my channel mathstips4u.<br />In this video we are going to learn disjunction and its truth table.<br />In the last video we have seen conjunction and its truth table and some of its examples. Out of these examples some of them were left for you as exercise. <br />I promised that I shall provide you answers in this video. The answers are at the end this video. <br />If you are new visitor before watching this video, please watch my video on conjunction.<br />So let’s begin with <br />Disjunction(V):<br />A compound statement is formed by using two simple statements and connective ‘or’ is called disjunction.<br />In Mathematics ‘or’ is used in the inclusive sense. Thus ‘p or q’ means p or q or both p and q, where p, q are two simple statements.<br />The disjunction ‘p or q’ is false only when both p and q are false. In all other cases, ‘p or q’ is true.<br />Truth table of disjunction p V q<br />p q p V q<br />T T T<br />T F T<br />F T T<br />F F F<br />Ex. Express following in symbolic form.<br />1. Sanjay will go to Pune or Nasik.<br />2. Four or five students did not attend the lectures.<br />I will solve 1st example, remaining is left for you so try it, and if no possible don’t get panic. I will give the solution in my next video on negation. <br />Solution:<br />1. P: Sanjay will go to Pune.<br /> q: Sanjay will go to Nasik.<br />Symbolic form is p ᴠ q.<br />In this way we have seen disjunction and its truth table.<br />Answers of examples from my last video on conjunction.<br />2. Anil and Sunil belongs to the same caste.<br />→ Here ‘and’ is combined two nouns and not two simple statements. Hence it is not used as a connective. It expressed as <br />p: Anil and Sunil belongs to the same caste.<br />3. The drug is effective though it has side effects.<br />→P: The drug is effective, q: The drug has side effects.<br />Symbolic form is p Ʌ q<br />4. In spite of tight security Dena bank were robbed.<br />→p: Dena bank has tight security. q: Dena bank were robded.<br />Symbolic form is p Ʌ q.<br />In my next video we are going to learn negation and its truth table.<br />If you find my video useful, please subscribe my channel, like it, share it and comment.<br />Thanking you for watching my video.<br />
