This is a discussion on *1=0.* within the **A Brief History of Cprogramming.com** forums, part of the Community Boards category; Originally Posted by cpjust
Shouldn't those both equal 0? Anything times 0 equals 0 right?
But isn't infinity large enough ...

- 08-18-2008 #46

- Join Date
- Jul 2007
- Location
- Farncombe, Surrey, England
- Posts
- 15,677

- 08-18-2008 #47

- Join Date
- Jun 2006
- Location
- Toronto
- Posts
- 591

infinity * zero is undefined as is 5/0. the limit of the latter is another story (inf).

- 08-18-2008 #48

- Join Date
- Aug 2007
- Location
- Toronto, ON
- Posts
- 3,545

- 08-18-2008 #49

- 08-18-2008 #50

- Join Date
- Aug 2007
- Location
- Toronto, ON
- Posts
- 3,545

- 08-18-2008 #51
Well to begin with infinity is not a number. You really can't multiply, divide, add, or subtract it. We can however talk about a function that goes to infinity given a certain condition.

inf * 0 is an indeterminate form as it depends on what f(x) and g(x) really are. Say f(x) goes to infinity twice as fast as g(x) goes to 0 you'll get a different result then if the situation was reversed.

- 08-19-2008 #52

- 08-19-2008 #53

- 08-19-2008 #54

- Join Date
- Jan 2005
- Posts
- 7,319

>> And since when did canceling in multiplication give zero?

1 = 0. See first post.

- 08-19-2008 #55
I think he thinks that:

Code:x * 0 = 1 * 0 = 0 = 0 - - - - - 0 x 0 1 0

- 08-19-2008 #56

- Join Date
- Aug 2007
- Location
- Toronto, ON
- Posts
- 3,545

Well it's been a while since I've done that kind of math, but now that I think of it, yes that's what I meant.

But putting all the math stuff aside for a second - aren't 0 and infinity exact opposites?

I mean infinity is basically everything, whereas 0 is nothing. So combine them together and they annihilate each other like matter and antimatter.

- 08-19-2008 #57
Um no. If anything would be opposites it would be inf and -inf but even those are just concepts.

Just think about this for a bit: Suppose you had f(x) and g(x). One goes to infinity and the other goes to zero as x approaches some value. Now if f(x) is changing faster then g(x) wouldn't you expect to get a different answer then if the g(x) was changing faster then f(x)?

- 08-19-2008 #58

- Join Date
- Aug 2007
- Location
- Toronto, ON
- Posts
- 3,545

- 08-19-2008 #59
Reread what I said again. One goes to inf and one goes to 0. Not that both go to inf.

- 08-19-2008 #60

- Join Date
- Aug 2007
- Location
- Toronto, ON
- Posts
- 3,545

- Exactly how to get started with C++ (or C) today
- C Tutorial
- C++ Tutorial
- 5 ways you can learn to program faster
- The 5 Most Common Problems New Programmers Face
- How to set up a compiler
- 8 Common programming Mistakes
- What is C++11?
- Creating a game, from start to finish

- How to create a shared library on Linux with GCC - December 30, 2011
- Enum classes and nullptr in C++11 - November 27, 2011
- Learn about The Hash Table - November 20, 2011
- Rvalue References and Move Semantics in C++11 - November 13, 2011
- C and C++ for Java Programmers - November 5, 2011
- A Gentle Introduction to C++ IO Streams - October 10, 2011