BIZNIQUE / LINEAR ALGEBRA / 18
Interpret an eigenvector geometrically
Interpret an eigenvector geometrically
Look for a direction that a matrix stretches without turning away from its span.
BIZNIQUE / LINEAR ALGEBRA / 18
Look for a direction that a matrix stretches without turning away from its span.
THE IDEA
An eigenvector remains on the same line after transformation; its eigenvalue gives the signed scale factor. For the symmetric example A = [[3, 1], [1, 3]], the diagonal directions have eigenvalues 4 and 2.
Av = λv, for v ≠ 0
Eigenvectors can reverse direction when the eigenvalue is negative. General real matrices need not have a complete real eigenbasis.
TRY IT YOURSELF
What happens to v = (1, 1) under this example matrix?
Av = (4, 4) = 4v, so v is an eigenvector with eigenvalue 4.