实对称矩阵的正交相似变换矩阵的求解

Resolution of Orthogonal Similar Transformation of Real Symmetric Matrix

n阶实对称矩阵A必正交相似于一个对角阵，当A的特征方程存在重根时，求解正交相似变换矩阵有时需要对特征向量进行施密特（Schmidt）正交化，在给出三阶实对称矩阵的特征方程存在二重很及四阶实对称矩阵的特征方程存在三重根时，证明不需要进行施密特正交化就可得到正交相似变换矩阵的求解法，同时给出了另一个非重根的特征值对应的特征向量的简单求解法．

In this paper, we give a method to obtain the orthogonal similar transformation for the the 3 ×3 real symmetric matrix with a 2 multiplicity root and 4×4 real symmetric matrix with a 3 multiplicity root without using the Schmidt orthogonalization . On the other hand,we also give a simple method to obtain the eigenvector corresponding to eigenvalue in the case of real symmetric matrix without multiplicity root.