There is a model Q(t)= a1*A(t)+ a2*B(t)+ a3*A(t)^2*B(t)+ a4*A(t)*B(t) ^2+a5* B(t) ^3+ a6 A(t) ^3+ a7*A(t) ^2*C(t)
Where P(t), A(t), B(t) and C(t) are known for any point of time or a sample of time.
Then I want to obtain the value of a1, a2, a3,a4,a5,a6,a7 with constrained a1>0, a20,a4>0, a6>0, a5 and a7 unbounded
So that P(t)-Q(t) become minimum or negligible at any point of time.