Conceptual Understanding
在代数操作之前,先把可解性、秩与投影看作几何关系。

AX26-MATH-101 · 2026-27
从线性方程组出发,学习正交投影与最小二乘,并分析解的唯一性。
State when a linear system is solvable, relate projection to the normal equations, and distinguish uniqueness from numerical sensitivity.
01 Problem and prerequisites 15h
学习结果 Restate solvability in the language of span and linear combination.
形成性检查 四选一检查
02 Vectors and linear combinations 20h
学习结果 Decide whether a target vector lies in a stated span and justify the decision.
形成性检查 书面推导
03 Rank and solvability of linear systems 20h
学习结果 Relate rank of A and of the augmented matrix to existence of solutions.
形成性检查 四选一检查
04 Geometric foundations: orthogonality 20h
学习结果 Use an inner product to test orthogonality and to split a vector into parallel and perpendicular parts.
形成性检查 书面推导
05 Orthogonal projection 20h
学习结果 Derive the projection formula onto a subspace with an orthogonal or orthonormal generating set.
形成性检查 书面推导
06 Derivation: normal equations 25h
学习结果 Derive AᵀAx = Aᵀb from minimising ‖Ax−b‖² and state when the minimiser is unique.
形成性检查 书面推导
07 Uniqueness and conditioning 15h
学习结果 Give a rank condition for uniqueness and a counterexample where a small change in b changes x sharply.
形成性检查 反例
08 Methods and examination synthesis 15h
学习结果 Assemble a complete least-squares argument: existence, geometry, algebra, uniqueness.
形成性检查 书面推导
Given a concrete system or least-squares problem, produce a derivation that names rank, column space, and the normal equations, and say what uniqueness does and does not follow.
Row reduction, rank, orthogonality, orthogonal projection, normal equations, residual geometry.
Separate geometric claims from algebraic identities; write a short derivation that a reader can check line by line.
在代数操作之前,先把可解性、秩与投影看作几何关系。
处理一致性与投影问题,并写明所用条件。
推导正规方程,并把唯一性论证迁移到相关方程组。