I thought about posting this in "homework" but it is not school related - just hobby stuff...

Is there an easy way to solve second-order differential equations? Specifically, I would like to solve the equations found on this web page.

Can someone steer me toward a website explaining "erf" and "exp?"

My hope is to be able to graph carbon concentration versus depth for a given temperature, time, and starting carbon concentration.

Thank you.

 

Good sources for erf and exp functions, not for beginner though, the treatments are dry and concise. You need some background in math to follow the text.

http://mathworld.wolfram.com/Erf.html
http://mathworld.wolfram.com/ExponentialFunction.html

Are you into steel making? Good luck.

 

Not making my own steel yet, though a buddy of mine is doing so.

I'm into blacksmithing and knife-making. Decarburisation of the steel during forging and heat treating is a concern with some steels and some procedures. I'm just looking for the boundries of the "ballpark."

Edit And thank you for those links! I will wade through them as best I can.

 

You find the MathWorld site a little daunting to read, try: http://en.wikipedia.org/wiki/Error_function

You may also want to do a search for "Error Function Tables", which will give the solution to erfc(x) for different values of x. Its a little easilr than wading through the calculus.

Exp is just the simple exponential function, defined as:

e^x = 1 + x + x^2/2! + x^3/3! + x^4/4! .........

And this is easily solved with many calculators.

Dave

 

Originally posted by Dave@Dec 19 2005, 04:24 PM
You find the MathWorld site a little daunting to read, try: http://en.wikipedia.org/wiki/Error_function

You may also want to do a search for "Error Function Tables", which will give the solution to erfc(x) for different values of x. Its a little easilr than wading through the calculus.

Exp is just the simple exponential function, defined as:

e^x = 1 + x + x^2/2! + x^3/3! + x^4/4! .........

And this is easily solved with many calculators.

Dave

[post=12574]Quoted post[/post]​

Sweet! Thanks Dave! Thirty seconds on Google was all it took to find an error function table!