Math Is Fun Forum

Hannibal lecter

Member

Registered: 2016-02-11

Posts: 392

another question about the slope!

Hi,

before you see my question please look to that following picture :-

please if the slope is two inches per year,  between 146 and 138 (Rise) and 8 - 4 (Run)  and every two points between Run(8-4) from this  Table. 1.2

I understand that and it is too clear... BUT!! my question is :- how to determine the slope in the same line between (146-133)= Rise!  or in any value and versus Run(8-3)>Run...... these numbers I chose just for example cause that I mean is "why when I chose any value in the same line I don't get the same slope!!!! shouldn't be the same slope"2 pear year" ,, is there an error???     
and the picture says : using any other two points on the line gives the same value.*

but I didn't get the same value when I chose any number why why why

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Wisdom is a tree which grows in the heart and fruits on the tongue

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: another question about the slope!

Hi;

That is a linear equation ( straight line ) the slope is constant.

May I see your calculations for the slope that do not end up with an answer of 2?

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Hannibal lecter

Member

Registered: 2016-02-11

Posts: 392

Re: another question about the slope!

I try some numbers between number 146 and 138 and I mention that as an example, but take this : 145-131/8-4 = 3.5

so now it is between two points and it is 3.5 not 2,

can I know why that is happen? maybe I can find the slop of simple functions but I want to know further and further than that,

just tell me the reason please.

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Wisdom is a tree which grows in the heart and fruits on the tongue

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: another question about the slope!

Hi;

Your denominators are incorrect.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Hannibal lecter

Member

Registered: 2016-02-11

Posts: 392

Re: another question about the slope!

but from where did you get this denominators? how did you find it

please learn me how to do that.

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Wisdom is a tree which grows in the heart and fruits on the tongue

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: another question about the slope!

The problem is in that horrid Rise / Run notation. It masks the fact that the calculation, not what those blasted theoreticians do, is done using coordinates.

In the days of yore we used to write it this way:

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Hannibal lecter

Member

Registered: 2016-02-11

Posts: 392

Re: another question about the slope!

I know, but from where did you the x2-x1? I mean how did you het the change in x,

may you tell me that

I just want to get the slop in any any point in the line any point I like and I want that not just from this table,

Last edited by Hannibal lecter (2016-11-27 07:22:42)

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Wisdom is a tree which grows in the heart and fruits on the tongue

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: another question about the slope!

Hi;

In simplest terms and no jargon, here is how:

You have two points (x1,y1) and (x2,y2). Form a fraction and on top do x2 - x1 and on the bottom do y2 - y1. Reduce the fraction and you are done.

The two points you are either given or you need to use the equation to get them.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.