Recent content by sciencegirl1

When finding eigenvectors in matrices I choose something for some x-es. Like sometimes x3 or x4 is chosen to be s or t or 2s etc... What I´d like to ask about is, does it not matter what the number is? Can I chose whatever I want to? If the matrix has 3 eigenvalues and after gauss...

tiny-tim I do not recommend you becomming a teacher.

lamda is 3 and then you find k? But in problems like this, do I always know that there is only one eigenvalue?

I do know that Ax= [-15, -11+3k, 9] Then I have to find \\lamda * [-5, -2, 3] = [-15, -11+3k, 9] therefore -5 \\lamda -2\\lamda + 3\\lamda =-15 and = 9 and = -11+3k ?

3 2 5]^T why do you use this vector. The vector is -5 -2 3 and why use T? Can you just show me how to do this simply?

What I need is the way to solve this problem. Step by step. I don´t need to understand it. I can´t see why you don´t want to help me.

can you show me how you do it?

So I do -15/3=-5 9/3=3 and -11+5k=-2 and therefore k=5/3 ??

i don´t know... can you help me solve this? I don´t have that much time left.

thanks tiny tim you´re a live saver when I multiply it I get -15 -11+3k 9 Then I don´t know what to do :(

Thanks a lot everybody!

2 1 -1 1 3 k -1 -5 -2 -5 -2 3 You´re right. This wasn´t the right A. Sorry. This one is correct :)

Homework Statement A= 1 5 2 1 3 k 2 1 1 Solve for k if A has the eigenvector 3 2 5 The Attempt at a Solution I first tried to put in eigenvalues L1, L2 and L3 2-L1 [3-L1, k ; -5 , -2-L1] and so on... and was going to isolate k but it doesnt´make any sense to me...

thanks for your help i just don´t know how to solve it :( I´be been trying but is there any rule for solving equations like this or...?

so you'll have a cubic polynomial in LaTeX Code: \\lambda that is equal to zero. You need to solve for LaTeX Code: \\lambda in that polynomial. can you show me?