I read in wikipedia

kindly explain me this.

Instead of writingf(x) we write M(v) where M is a matrix and v is a vector.Kindly explian this with example..

The rules for using a matrix to transform a vector are given in the article linear algebra.

If the action of a matrix on a (nonzero) vector changes its magnitude but not its direction, then the vector is called an eigenvector of that matrix.