Question

at http://tutorial.math.lamar.edu/Classes/DE/RealEigenvalues.aspx in second example how do we make the cross shaped graph on the basis of eigenvalues & eigenvectors?

Answer 1

You can plot the eigenvectors . Then draw a line between their end-point and the origin.
in other words, the eigenvectors point in some direction, with their tail at the origin and their head at the plotted point.

Answer 2

if you scale them by a constant, you can move up and down along them, so they can represent a line.

Answer 3

Ok in this case the n_1 (eta_1) is ( -1 1) so I can see it on the graph but the n_2 (eta_2) is (2 3) how he drew it on the graph

Answer 4

crystal clear thanks a tonne bro