12/4/2008

Problem Session

Finding eigenvectors

For each eigenvalue, we find the eigenspace, which is the kernel of the matrix A - (lamda) I. The eigenvectors associated with each eigenvalue are the nonzero vectors in the eigenspace.

Algebraic versus Geometric Multiplicity

The algebraic multiplicity is determined by looking at the characteristic polynomial

The geometric multiplicity is determined by the dimension of the eigenspace.

Eigenbasis

An eigenbasis for A is a basis for R^n consisting of the eigenvectors of A.

Existence

If an n x n matrix A has n distinct eigenvalues, then there exists an eigenbasis for A.

Diagonalization

An n x n matrix A is diagonalizable if and only if there exists an eigenbasis for A.

Group/Class Exercises

Section 7.3 - 1, 4, 9, 15, 20, 22, 36, 44

Section 7.4 - 1, 2, 6, 14, 22, 26, 32

Please read Section 5.5 for class on Tuesday