Change from exponent

[CanucksRule]

Hey

I need to change this equasion around so that it doesnt use the exponent function. i know you can do it, i just how. Any suggestions, in desperate need of help. An example of what values my be in the variables are:

Best_A = 22.164
Best_B = 2.813
Best_h0 = 1.008
Y = 0.4

X = Best_A * (Y - Best_H0) ^ Best_B

Thanks

[DiGiTaIErRoR]

The result is imaginary.

VB math doesn't do imaginary numbers.

I'd suggest On Error Goto sub handling.

[krtxmrtz]

Originally posted by CanucksRule
Best_A = 22.164
Best_B = 2.813
Best_h0 = 1.008
Y = 0.4

X = Best_A * (Y - Best_H0) ^ Best_B

You still can operate with imaginary numbers as long as you stick to the rules. For example, (Y - Best_H0) ^ Best_B could be expressed as:

(0.4 - 1.008)^2.813 = (-0.608)^2.813 = (-1)^2.813 * (0.608)^2.813 = (-1)^2.813 * 0.247 (approx.)

Call x the first (imaginary) term and compute it as:

x = (-1)^2.813
ln(x) = 2.813 ln(-1) = 2.813*i*Pi (because -1 = exp(i*Pi))
where i=Sqr(-1)

so:

x = exp(2.813*i*Pi) = cos(2.813*Pi) + i*sin(2.813*Pi) = 0.988 + i*0.154

And finally you get:

(0.988 + i*0.154)*0.247 = 0.244 + i*0.038 (approx.)

(and now multiply this by Best_A)