#uregina120 - #81- proof by contradiction
Channel: Jeffrey Cliff
Date: 2015-09-30

Donations: 
1DfVCdrmUd3kuUMMayHvd6AEMtP6ZNNwvo

Prerequisites:

https://www.youtube.com/watch?v=khgOUhczgkQ&list=PL0KBVEO7tItfL6wmsngECFbweUsaPmhIE&index=5
https://www.youtube.com/watch?v=nG3Jkif_q7g&list=PL0KBVEO7tItfL6wmsngECFbweUsaPmhIE&index=17
https://www.youtube.com/watch?v=9DTXYf8DqUg&index=78&list=PL0KBVEO7tItfL6wmsngECFbweUsaPmhIE
https://www.youtube.com/watch?v=DMhqrmjaVzI&index=77&list=PL0KBVEO7tItfL6wmsngECFbweUsaPmhIE
https://www.youtube.com/watch?v=ufPKEMX03PQ&index=7&list=PL0KBVEO7tItfL6wmsngECFbweUsaPmhIE
https://www.youtube.com/watch?v=lWFn8yxJlmY&index=11&list=PL0KBVEO7tItfL6wmsngECFbweUsaPmhIE

Sources:

https://en.wikipedia.org/wiki/Proof_by_contradiction
https://gowers.wordpress.com/2010/03/28/when-is-proof-by-contradiction-necessary/
http://mathworld.wolfram.com/ProofbyContradiction.html