Product Of Slopes Of X,y Axes=0

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Discussion Overview

The discussion revolves around the slopes of the x-axis and y-axis, particularly focusing on the product of these slopes and its implications regarding perpendicular lines. Participants explore the mathematical properties and definitions of slopes in the context of geometry and limits.

Discussion Character

  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant asserts that the slope of the y-axis (x=0) is +1 and the slope of the x-axis (y=0) is 0, leading to a product of slopes equal to 0, which they question as a contradiction to the rule that the product of slopes of perpendicular lines should equal -1.
  • Another participant humorously points out a misunderstanding regarding the slopes, suggesting that the y-axis does not have a slope of +1.
  • Several participants engage in a back-and-forth about the correct interpretation of the slopes, with one emphasizing that the slope of the y-axis is actually infinite.
  • A participant introduces the idea that infinity multiplied by zero could yield -1, prompting confusion and further questioning about the validity of this statement.
  • Another participant clarifies that infinity multiplied by zero does not make sense and discusses limits in the context of slopes approaching infinity.
  • One participant presents a mathematical example involving two lines with slopes that are perpendicular, exploring the limits as parameters approach infinity and concluding that the product of the slopes remains -1 under those conditions.
  • Responses to the mathematical conjecture vary, with some participants expressing confusion about the terminology used and others seeking clarification on the meaning of "conjecture."

Areas of Agreement / Disagreement

Participants do not reach a consensus on the slopes of the axes or the implications of their product. There are competing views on the interpretation of slopes and the validity of certain mathematical statements, leading to an unresolved discussion.

Contextual Notes

There are limitations in the discussion regarding the definitions of slopes, the treatment of infinity in multiplication, and the assumptions made about the behavior of limits. These aspects remain unresolved and are subject to interpretation.

extreme_machinations
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This Is Strange !

Slope Of The Line X= 0[y- Axis] Is =+1
Slope Of The Line Y=0 [x-axis] Is= 0
Product Of The Slopes = 0

Now Product Of Two Perpendicular Lines Should Be = - 1

Is There A Contradiction ??
 
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It's funny how both the y-axis and the line y=x have the same gradient according to you :-p
 
well ,
its even funnier how lack of reading skills can hamper a persons understanding .

if u pay attention sire ,u'll find that i said
that the line y=0 ,which you would agree is the x - axis and has a slope = 0
 
extreme_machinations said:
well ,
its even funnier how lack of reading skills can hamper a persons understanding .

if u pay attention sire ,u'll find that i said
that the line y=0 ,which you would agree is the x - axis and has a slope = 0
I don't disagree with you, but do you know what the gradient of the line x=0 (the y-axis) is?

If you work that out you will understand where you went wrong. Please don't be so offended I was just lightly trying to point out your mistake.
 
This reminds me of the "proof" that 1 = 2. The mistake involved dividing by zero or something. ;)
 
extreme_machinations said:
well ,
its even funnier how lack of reading skills can hamper a persons understanding .

if u pay attention sire ,u'll find that i said
that the line y=0 ,which you would agree is the x - axis and has a slope = 0

Good advice. You should take it yourself. Zurtex did not say anything about "the line y=0, which you would agree is the x-axis". He specifically referred to the "y-axis" and his point was that its slope is not 1!
 
The slope of the y-axis (x=0) is infinite. And, as we all know, infinity times zero equals negative 1. :)
 
oopsey !
tan 45 syndrome !
sorry for that ,

but i thought anything multiplied by 0 is = 0
infinity multiplied by zero being -1 is brand new information to me ,can anyone tell me how this so ??
 
extreme_machinations said:
oopsey !
tan 45 syndrome !
sorry for that ,

but i thought anything multiplied by 0 is = 0
infinity multiplied by zero being -1 is brand new information to me ,can anyone tell me how this so ??
Infinity multiplied by 0 is not -1, heck it doesn't even make sense. But what you can do is work out the limit of the 2 sides when multiplied by each other, which goes something like this:

\lim_{x \rightarrow \infty} -x \frac{1}{x} = -1

Now although it's true that:

\lim_{x \rightarrow \infty} -x = -\infty

And:

\lim_{x \rightarrow \infty} \frac{1}{x} = 0

It only makes sense to say:

\lim_{x \rightarrow \infty} f(x) g(x) = \left( \lim_{x \rightarrow \infty} f(x) \right) \left( \lim_{x \rightarrow \infty} g(x) \right)

If f(x) and g(x) have limits as x approaches infinity. And as we see above -x has no limit as x approaches infinity.
 
  • #10
Consider the following two lines:

Line A: y = -nx
Line B: y = x/n

The gradients of these two lines are:

Line A: gradient = -n
Line B: gradient = 1/n

Because any two lines which are perpendicular have gradients which multiply to give -1, we see immediately that line A is perpendicular to line B, for any given value of n.

Now, consider what happens in the limit as n goes to infinity. For line B we have:

\lim_{n \rightarrow \infty} y = \lim_{n \rightarrow \infty} x/n = 0

So, line B becomes the line y = 0.

We can write line A as:

x = -y/n

Taking the limit as n goes to infinity, we see that this line becomes the line x = 0.

Since we have taken the same limit in both cases, the lines A and B have remained perpendicular, and their gradients must still multiply to give -1. What we have, n terms of the gradients, is:

\lim_{n \rightarrow \infty} (-n)(1/n) = \lim_{n \rightarrow \infty} -1 = -1
 
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  • #11
hey that's great conjecture !

thanks
 
  • #12
extreme_machinations said:
hey that's great conjecture !

thanks


What "conjecture" are you talking about? I didn't see any conjecture in this.
 
  • #13
I Was Just Using It In The General Sense ,not Strictly In The Mathematical Sense .

Please Ignore Whatever Does'nt Make Sense To You .
 
  • #14
What general sense then? I thought I knew what "conjecture" meant, even in general- and I don't see how it applies. Enlighten me.
 
  • #15
ok ,you win pal !
im not going to argue .
tell me what it was .

peace out ,
 

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