You are here
How to prove a Proposition as True or False
Last updated at October 5, 2026 by Teachoo
Maths Class 9
Chapter 9 Class 9 - Propositions and their Converses (Ganita Manjari)
-
Definition
- Examples
- Exercise Set 9.1
Transcript
How to prove a Proposition as True or False Now, To prove True, we have to cover very single case without exception To prove FALSE, we need one example which disproves it To prove TRUE: cover EVERY case Claim: The sum of any two consecutive positive integers is odd. ome examples: odd odd odd xamples support the claim. hey do not prove it. A general proof: Let the integers be and . Since is odd for every positive integer , the claim is TRUE. A general argument covers every case. An example that disproves a statement is called counterexample KEY TAKEAWAY TRUE → a proof covering every case FALSE → just one counterexample Testing even 10,000,000 cases is not a general proof. How to prove Statement as true Now, To prove True, we have to cover very single case without exception To prove FALSE, we need one example which disproves it An example that disproves a statement is called counterexample
