# Question: Why can't I find the eigenvectors when I can find the eigenvalues?

March 22 2013 by
false
Maple

0

Hey,

I have currently encountered a problem that I am not sure if is a mathematical problem or a problem with Maple itself. I want to find the eigenvalues and eigenvectors of the following matrix:

[[2.460*10^9*sin(theta)^2+8.970*10^6*cos(theta)^2, 0, 2.449*10^9*sin(theta)*cos(theta)], [0,8.450*10^6*sin(theta)^2+8.970*10^6*cos(theta)^2,0],[2.449*10^9*sin(theta)*cos(theta),8.970*10^6*sin(theta)^2+2.530*10^9*cos(theta)^2]]

Maple is able to conjure up three lengthy expressions for the eigenvalues, but when I try to find the eigenvectors I get the errormessage "Error, (in LinearAlgebra:-Eigenvectors) invalid input: rhs received [], which is not valid for its 1st argument, expr". If I insert a value for theta beforehand, then calculating the eigenvectors is no problem.

Is this a mathematical issue due to the trigonometric functions, or is it Maple failing me?

Thanks, Erik.