Hi,
I am a new user and I need help.
My problem is that have some data(x,y) and I done a chart for them.
However, I need to draw a curve which has this type: y=ax/(1+ax) and
then I draw the erros. I don't know how I can implement this equation.
Could someone help me? It is urgent for me.
In the attachment image you can see what I want exactly.
Thanks.


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|Filename: curve.JPG |
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bevag
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use the trendline with your chart


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cartera
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The trendline is defined by excel (linear, exponential, power etc.). I
don't want to add one fo these trendlines. I want to use as trendline
this equation y=ax/(1+ax)


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bevag
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Ummm...you can rewrite the equation y=ax/(1+ax) as
1/y = 1/(ax)+1 as long as you have no y=0 or x=0 points.

Substitute y'=1/y, x'=1/x and you get y'=a'x'+1, with a'=1/a.

Solve the linear equation with LINEST or a chart trendline.

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Regards,

Tushar Mehta
www.tushar-mehta.com
Excel, PowerPoint, and VBA add-ins, tutorials
Custom MS Office productivity solutions

In article , bevag.2cpfi5
says...

Hi,
I am a new user and I need help.
My problem is that have some data(x,y) and I done a chart for them.
However, I need to draw a curve which has this type: y=ax/(1+ax) and
then I draw the erros. I don't know how I can implement this equation.
Could someone help me? It is urgent for me.
In the attachment image you can see what I want exactly.
Thanks.


+-------------------------------------------------------------------+
|Filename: curve.JPG |
|Download: http://www.excelforum.com/attachment.php?postid=5227 |
+-------------------------------------------------------------------+

--
bevag
------------------------------------------------------------------------
bevag's Profile: http://www.excelforum.com/member.php...o&userid=37679
View this thread: http://www.excelforum.com/showthread...hreadid=572871