家里蹲大学数学杂志第3卷第76期_北京师范大学2006年数学分析与高等代数考研试题参考解答.pdf The author would like to thank Mr. W. Zhang for sending him the problems within this paper last day. When this work was being done, some errors (perhaps) was found, see Problem 5 (c) (In the original problem, the 1/3 is missing.) By the way, most of the problems are interesting.And I havewasted in thinking for a period of time... Remark: Maybe the perpendicular part of a subvector space should be replaced by the span of some linearly independent vectors...Wish you could write the answer by yourself.