Talk:Pendulum (mathematics)

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I don't think the Figure 4 is right, because you see, the deviation should increase ever more with the increasing angle amplitude and reach Infinity at amplitude Pi, so the derivative of such graph never starts bending to the right, but it is always convex. -Bole79 12:59, 11 January 2007 (UTC)

I made the picture. To tell the truth, I wasn't really sure about the result I got, but I just plotted the formula in the document. To check whether I made any mistake, you can click on the picture and you'll find the approach and the code I have used to make it. Find what is wrong (in the article or in my code) and I will fix it Alessio Damato 13:08, 11 January 2007 (UTC)

[edit] The formular for the elliptic function for T under Arbitary-amplitude period

Using excel I have tried to plot the function given for T My graph peaks at 180 degrees and there is no sign of it going to infinity. The equation which seems to fit with the curve in fig 4 is as follows:-

           Replace (SIN(Theta/2))^2    with  ((SIN(Theta))/2)^2
           Replace (SIN(Theta/2))^4    with  ((SIN(Theta))/2)^4
           Replace (SIN(Theta/2))^6    with  ((SIN(Theta))/2)^6

             and so on
        With five terms this gives a curve very similar to Figure 4 otherwise I could
not repeat the curve shown. (it went to 1.488 not 1.073)

Regards

       John wayman 00:09, 12 February 2007 (UTC)