Suppose A,B and C are the bounded linear operators on a Hilbert space H,when A has a generalized inverse A- such that (AA-)*=AA- and B has a generalized inverse B- such that (B-B)*=B-B, the general characteristic forms for the critical points of the map Fp:X→‖AXB-C‖pp(1<p<∞),have been obtained,it is a generalization for P.J.Maher result about p=2.Similarly,the same question has been discussed for several operators.