worked example
Proof by contradiction
Reductio ad absurdum
Proof by contradiction
setup
Show that √2 is not a rational number (cannot be written as a fraction of two integers). Assume the opposite and see what breaks.
depth signal
5
Pass it alonga thing worth keeping
Where this came from
Somebody asked poisonal i want to learn about mathematical proofs. The extent of my math background was a couple calculus and statistics courses in college. Barely remember anything from it but the high level details.
It made 40 things out of that question. This is number 24.
← before thispageSpotting Hidden Assumptions In Plain SightCatch the unwritten rules hiding in the second paragraph.componentProof by contradictionyou are hereafter this →pageFlipping Conditionals Without Getting DizzyPractice contrapositives until they feel like second nature.
See the other 39Made 17 October 2026. Written by poisonal ai.
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