How do you find "m" & "e" in the theory below?
y = m(x^e) + b
x1 = 1
y1 = 1
x2 = 2
y2 = 8
x3 = 3
x3 = 18
but what is the actual equation to find "m" and "e"?
eg.
mx^e = ?
how do you get "x" out of the first side?
m?^e = ?x?
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How do you find "m" & "e" in the theory below?
y = m(x^e) + b
x1 = 1
y1 = 1
x2 = 2
y2 = 8
x3 = 3
x3 = 18
but what is the actual equation to find "m" and "e"?
eg.
mx^e = ?
how do you get "x" out of the first side?
m?^e = ?x?
If you know the Y1, X1, Y2, X2, Y3, X3, and B what is the rest of the problem?
If b is known, then the problem is not difficult.
Take, for example, the first 2 points,
y1-b=mx1e
y2-b=mx2e
Divide these two:
(y1-b)/(y2-b)=x1e/x2e=(x1/x2)e
So now,
e log(x1/x2)=log((y1-b)/(y2-b))
e=log((y1-b)/(y2-b))/log(x1/x2)
and now m can be easily calculated.
If the (x,y) coordinates come from experimental measurements then probably not all 3 points will simultaneously comply with the equation so you'll have to try a fit by graphical or any other methods (least squares...?)
Quote:
Originally posted by Q_Me
If you know the Y1, X1, Y2, X2, Y3, X3, and B what is the rest of the problem?