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# Exponential curve watch

1. Hi,

For the equation y = 1 / (1+9exp(-x)) I seem to get an S like shape from x=0 to x=8, with the head continuing along the line y=1. There's supposed to be something to observe at y = 0.5, but as far as I can see there's nothing remarkable, except that its virtually linear at this point. Should I be noticing something further?

Cheers.
2. For others wanting to see:

http://www.shodor.org/interactivate/...her/index.html

Put in "1 / (1+9*exp(-x))"

I suppose it's a sort of point of inflection. I could be wrong. I'm not sure of the exact definition of one, but I've only seen them where positive gradients meet negative ones.

-Chris
3. there are no turning point on that entire curve as the gradient is never 0.

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Updated: April 12, 2006
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