You are here
Misc 6 (i) - Mathematical Reasoning
Last updated at April 16, 2024 by Teachoo
Proving True - By Contradiction
Mathematical Reasoning
Concept wise
- Statements
- Writing negation of statements
- Negation - Checking if true or not
- Finding Compound Statement
- Words 'And' & 'Or'
- Inclusive and exclusive or
- Quantifiers
- Contrapositive and converse
- If then
- If and only if
- Proving not true/false (by giving counter examples)
- Proving True - If and only if
- Proving True - By Contrapositive
-
Proving True - By Contradiction
- Necessary and sufficient condition
Transcript
Misc 6 Check the validity of the statements given below by the method given against it. p: The sum of an irrational number and a rational number is irrational (by contradiction method). (i) The given statement is as follows. p: the sum of an irrational number and a rational number is irrational. Let us assume that the given statement, p, is false. That is, we assume that the sum of an irrational number and a rational number is rational. Therefore, a + b c = d e , where a is irrational and b, c, d, e are integers. d e = b c is a rational number and a is an irrational number. This is a contradiction. Therefore, our assumption is wrong. Therefore, the sum of an irrational number and a rational number is rational. Thus, the given statement is true.
