Matrix d1 using coeff as given in cramer 's rule
double [ , ] d1 = { { coeff [ 0 , 3 ] , coeff [ 0 , 1 ] , coeff [ 0 , 2 ] } , { coeff [ 1 , 3 ] , coeff [ 1 , 1 ] , coeff [ 1 , 2 ] } , { coeff [ 2 , 3 ] , coeff [ 2 , 1 ] , coeff [ 2 , 2 ] } , } ;