For Matrix A and Vector B, the LeastSquares(A, B) command returns a Vector that best satisfies the condition  is approximately equal to B, in the least squares sense. The result that is returned is the Vector x which minimizes Norm(A . x - B, 2).

Parameter A can also be a set of equations that describe the linear least squares problem. In this case, B is the set of variables in which the equations in A occur.