30 May
2018
30 May
'18
2:55 p.m.
On 2018-05-29 09:59, Mike Stay wrote:
My favorite irrationality proof is one I heard from John Baez. Suppose the cube root of two were not irrational; then there would be two positive integers p, q such that p/q = ∛2. Multiplying both sides by q and cubing, we get p³ = 2q³ = q³ + q³, which has no solutions in the positive integers by Fermat's Last Theorem!
I just read this aloud to Rohan, who remarked "You can also use that for ∛9.", barely looking up from his video game. --rwg