# How can I build power function through point?

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Irene Dzhavadova on 15 Jan 2019
Commented: Irene Dzhavadova on 16 Jan 2019
Please, help me! I have the coordinates of the curve y = [150 150 130 130 130 100 100 100 80 80 80 60], x = [52000 70000 74000 96000 100000 170000 220000 245000 530000 720000 810000 4900000]. This curve well described by power function. How can I build the same curve passing through the point A(68856, 210) and get it equation?
Torsten on 16 Jan 2019
If points are added, you will have to fit your model again. As a result, you'll get different values for a, b and c.

Sayyed Ahmad on 16 Jan 2019
I would do something like this:
x = [52000 70000 74000 96000 100000 170000 220000 245000 530000 720000 810000 4900000];
y = [150 150 130 130 130 100 100 100 80 80 80 60];
p=polyfit(log(x),sqrt(y),2)
x1=linspace(min(x),max(x),100);
y1=polyval(p,log(x1)).^2;
plot(x,y,'r*',x1,y1,'b-')
I hope that is waht you looking for.
Irene Dzhavadova on 16 Jan 2019
Sayyed Ahmad, thanks! I'll try this.

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