I need to find formula for this function:
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What is good program for nonlinear regression that could help me?
At the moment, I'm using this formula: Y*X=22,5
or I*V=22,5 Watt
but its not very precise.
BTW, I'm a total newbie. It seems that all programs require knowledge of function form and then they calculate parameters, right? So what form should I use?