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My first math teacher taught us division by zero was infinity. He justified it by showing division by 1, then fractions, and how the line goes up towards infin
by axaxs 6y ago
My first math teacher taught us division by zero was infinity. He justified it by showing division by 1, then fractions, and how the line goes up towards infinity. Today this is seen as incorrect, but it still makes more sense to me than other divide by zero explosions...
- b0rsuk 6y agoSounds nice at first, but if you poke some more you run into inconsistencies. This 9 minute video by Eddie Woo shows some. https://www.youtube.com/watch?v=J2z5uzqxJNU https://www.youtube.com/watch?v=J2z5uzqxJNU Spoiler: A major one goes like this. Suppose X/0 is infinity. Then: 1/0 = infinity 2/0 = infinity Therefore, 1 = 2.
- mamcx 6y agoI think this show something similar to this: https://en.wikipedia.org/wiki/Monty_Hall_problem https://en.wikipedia.org/wiki/Monty_Hall_problem 1 = 2 can't be evaluate in isolation, because in this case is 1 = 2 AFTER x/0 = infinity?
- lixtra 6y agoBut why not minus infinity? As the same argument holds by approaching from -1, -1/n.
- colechristensen 6y agoWell, if you add nuance, it’s fine. The limit of a number divided by another number x as x approaches zero is infinity. That’s almost the same thing. Much of math just doesn’t work if you try to add infinity as just another number. You say dividing by zero is undefined because once you have that infinity anything further you do with it is also going to be infinity, it breaks the way you prove things, it breaks the idea of a number line. There is plenty of math that deals with infinities, but it is all handled delicately.