Question: Optimization Assistant Fail

Hi

I want to find the optimum of

G*(.7500000000*B*sqrt((1.-2.*a+a^2)*B^2/(a^2+B^2-2.*B^2*a+B^2*a^2))-.7500000000*B*sqrt((1.-2.*a+a^2)*B^2/(a^2+B^2-2.*B^2*a+B^2*a^2))*a+.7500000000*a*sqrt(a^2/(a^2+B^2-2.*B^2*a+B^2*a^2)))

+

(1-G)*(-6.250000000*10^(-12)*sqrt(a^2/(a^2+B^2-2.*B^2*a+B^2*a^2))*(5.833333333*10^9*B*sqrt((1.-2.*a+a^2)*B^2/(a^2+B^2-2.*B^2*a+B^2*a^2))-7.500000000*10^9)*(4.*a-3.*B*sqrt((1.-2.*a+a^2)*B^2/(a^2+B^2-2.*B^2*a+B^2*a^2))+3.*B*sqrt((1.-2.*a+a^2)*B^2/(a^2+B^2-2.*B^2*a+B^2*a^2))*a-3.*a*sqrt(a^2/(a^2+B^2-2.*B^2*a+B^2*a^2)))^2-6.250000000*10^(-12)*(5.833333333*10^9*sqrt(a^2/(a^2+B^2-2.*B^2*a+B^2*a^2))-7.500000000*10^9)*B*sqrt((1.-2.*a+a^2)*B^2/(a^2+B^2-2.*B^2*a+B^2*a^2))*(4.-4.*a-3.*B*sqrt((1.-2.*a+a^2)*B^2/(a^2+B^2-2.*B^2*a+B^2*a^2))+3.*B*sqrt((1.-2.*a+a^2)*B^2/(a^2+B^2-2.*B^2*a+B^2*a^2))*a-3.*a*sqrt(a^2/(a^2+B^2-2.*B^2*a+B^2*a^2)))^2+0.3645833333e-1*sqrt(a^2/(a^2+B^2-2.*B^2*a+B^2*a^2))*B*sqrt((1.-2.*a+a^2)*B^2/(a^2+B^2-2.*B^2*a+B^2*a^2))*(4.-3.*B*sqrt((1.-2.*a+a^2)*B^2/(a^2+B^2-2.*B^2*a+B^2*a^2))+3.*B*sqrt((1.-2.*a+a^2)*B^2/(a^2+B^2-2.*B^2*a+B^2*a^2))*a-3.*a*sqrt(a^2/(a^2+B^2-2.*B^2*a+B^2*a^2)))^2+5.625000000*10^(-11)*(1.000000000*10^10+5.833333333*10^9*sqrt(a^2/(a^2+B^2-2.*B^2*a+B^2*a^2))*B*sqrt((1.-2.*a+a^2)*B^2/(a^2+B^2-2.*B^2*a+B^2*a^2))-7.500000000*10^9*B*sqrt((1.-2.*a+a^2)*B^2/(a^2+B^2-2.*B^2*a+B^2*a^2))-7.500000000*10^9*sqrt(a^2/(a^2+B^2-2.*B^2*a+B^2*a^2)))*(-1.*B*sqrt((1.-2.*a+a^2)*B^2/(a^2+B^2-2.*B^2*a+B^2*a^2))+B*sqrt((1.-2.*a+a^2)*B^2/(a^2+B^2-2.*B^2*a+B^2*a^2))*a-1.*a*sqrt(a^2/(a^2+B^2-2.*B^2*a+B^2*a^2)))^2)

for different values (maybe 100 different values) of G between 0 and 1. I put it into the optimization assistant, pick a value of G of 0.10, tell it to max, tell it a=0..1, B=0..1 (constraints), and it tells me, the optimum is

Objective value: .189835632710191270
 a = .500000000000000666
 B = 1

but then when I click plot, it is clearly not the optimum. why would maple make this mistake? what should I do?

thanks