
Paul E. answered 03/30/19
40 yrs experience math & engineering; 10 yrs tutoring all levels
An eigenvector of a linear transformation T is a vector v that is mapped to a multiple of itself by the transformation:
Tv = λv
In this equation, λ is a constant, called the eigenvalue associated with v.
The same terminology applies if A is a square matrix, and v a vector with Av = λv.