My Math Forum  

Go Back   My Math Forum > Math Forums > Math

Math General Math Forum - For general math related discussion and news

LinkBack Thread Tools Display Modes
November 24th, 2017, 06:28 AM   #1
Joined: Nov 2017
From: Portugal

Posts: 1
Thanks: 0

Use 0 in rule of 3?

Hello! I'm doing a AHK script. If 0 does nothing, 1 doubles, what do I do with this: (16/9)/0=(14/9)/x?
The number 0 in rule of three screws it all. I just want to have 0 as a normal number. I tried changing 0 to 1 and then subtract 1 from x. It gave me -0,125. I don't know if it worked or if it's even correct, so what can I do?
lmsrc is offline  
November 24th, 2017, 07:44 AM   #2
Math Team
Joined: Dec 2013
From: Colombia

Posts: 7,151
Thanks: 2390

Math Focus: Mainly analysis and algebra
You can't divide by zero.
v8archie is offline  
December 1st, 2017, 01:11 PM   #3
Math Team
Joined: Jan 2015
From: Alabama

Posts: 2,959
Thanks: 802

I haven't seen the term "rule of three" in years- and then in a very old book!

The "rule of three" is an old term for a proportion- given any three of a, b, c, or d in $\displaystyle a:b::c:d$ or (in more modern notation) $\displaystyle \frac{a}{b}= \frac{c}{d}$, you can solve for the fourth.

$\displaystyle \frac{a}{b}= \frac{c}{d}$ can also be written as $\displaystyle \frac{b}{a}= \frac{d}{c}$, $\displaystyle \frac{a}{c}= \frac{b}{d}$ or even $\displaystyle ad= bc$.

As others have said, you cannot divide by 0 so it makes no sense to write "$\displaystyle \frac{16/9}{0}= \frac{14/9}{x}$" but that can be written as $\displaystyle \frac{0}{16/9}= \frac{x}{14/9}$ which reduces very quickly to x= 0. In fact, in order for "$\displaystyle \frac{A}{0}= \frac{B}{x}$" to make sense, for any A, B, we must have x= 0.
Country Boy is offline  

  My Math Forum > Math Forums > Math


Thread Tools
Display Modes

Similar Threads
Thread Thread Starter Forum Replies Last Post
chain rule- constant rule ungeheuer Calculus 1 July 30th, 2013 06:10 PM
Product rule into chain rule unwisetome3 Calculus 4 October 19th, 2012 02:21 PM
how do yo solve this one using chain rule with quotient rule Peter1107 Calculus 1 September 8th, 2011 11:25 AM
Simpsons rule,Trapezoidal rule,check please manich44 Algebra 3 February 17th, 2010 10:23 AM
should i apply the product rule or quotient rule? mt055 Calculus 3 October 29th, 2009 11:58 PM

Copyright © 2018 My Math Forum. All rights reserved.