How to welcome a math PhD friend at the airport! @drpeyam

Dr Peyam is visiting Taiwan and this is how I welcomed him! @drpeyam We will investigate if the function f, defined from Q to R, such that f(x)=1 if x^2 is greater than 2 and f(x)=0 if x^2 is less than 2, is continuous or not. At first you might think f is discontinuous since there are jumps at x=+-sqrt(2), but we have to watch out for the domain! Such a classic real analysis question: Source: https://www.reddit.com/r/askmath/s/cy1aeuquja Shop your εδ sweatshirt: https://a.co/d/5jqQrPm 👉 Support this channel and get more content https://www.patreon.com/blackpenredpen #calculus #blackpenredpen