joshg253 to math · edit-22 years agoBottle, Burger, Beer, Hot Dog Viral Puzzle – Mind Your Decisionsmindyourdecisions.comexternal-linkmessage-square4fedilinkarrow-up16arrow-down10file-text
arrow-up16arrow-down1external-linkBottle, Burger, Beer, Hot Dog Viral Puzzle – Mind Your Decisionsmindyourdecisions.comjoshg253 to math · edit-22 years agomessage-square4fedilinkfile-text
“As viral puzzles became popular, mathematicians joined the game too. Here’s a fun puzzle that has been widely shared.”
minus-squaredeliallinkfedilinkarrow-up3·2 years agoThe first 3 lines are trivial, but it’s been a while since I did any calculus. Would you use integration by parts for it? Wolfram gives me: spoiler 5/2 🥧
minus-squareParsniplinkfedilinkarrow-up2·2 years agoI don’t think that would work. You just use the fact that the integral from negative to positive infinity of sin(x)/x is pi, so from 0 to infinity it is pi/2, which you can derive from using Feynman’s trick for computing weird integrals like these.
The first 3 lines are trivial, but it’s been a while since I did any calculus. Would you use integration by parts for it?
Wolfram gives me:
spoiler
5/2 🥧
Calculus was 20 years ago for me…
spoiler
I don’t think that would work. You just use the fact that the integral from negative to positive infinity of sin(x)/x is pi, so from 0 to infinity it is pi/2, which you can derive from using Feynman’s trick for computing weird integrals like these.
Ah, that’s the trick I was missing. Thx!