Solving equations for Eigenvector: Vanishing

zak100
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Homework Statement


I am trying to solve a Eigen vector matrix:

##\begin{bmatrix}9.2196& 6.488\\4.233& 2.9787\end{bmatrix}\cdot\begin{bmatrix}x\\y\end{bmatrix}-\lambda\begin{bmatrix}x\\y \end{bmatrix}=0##

I have found ##\lambda_1 = 0## and ##\lambda_2 = 12.1983##
However, I can't solve the following equations:
##9.2196x + 6.488y =0 -------(eq.1)##
and ##4.233x + 2.978y =0 ----(eq.2)##

I am multiplying ##(eq.1) ## by ##4.233x## and ##(eq.2)## by ##9.2196##

Some body please guide me how to solve these equations for ##x## and ##y## values.

Zulfi.

Homework Equations


##9.2196x + 6.488y =0 -------(eq.1)##
and ##4.233x + 2.978y =0 ----(eq.2)##​

The Attempt at a Solution


I am multiplying ##(eq.1)## by ##4.233## and ##(eq.2)## by ##9.2196## but both the equations are vanishing. Some body please guide me.

Zulfi.
 
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zak100 said:

Homework Statement


I am trying to solve a Eigen vector matrix:

##\begin{bmatrix}9.2196& 6.488\\4.233& 2.9787\end{bmatrix}\cdot\begin{bmatrix}x\\y\end{bmatrix}-\lambda\begin{bmatrix}x\\y \end{bmatrix}=0##

I have found ##\lambda_1 = 0## and ##\lambda_2 = 12.1983##
However, I can't solve the following equations:
##9.2196x + 6.488y =0 -------(eq.1)##
and ##4.233x + 2.978y =0 ----(eq.2)##

I am multiplying ##(eq.1) ## by ##4.233x## and ##(eq.2)## by ##9.2196##

Some body please guide me how to solve these equations for ##x## and ##y## values.

Zulfi.

Homework Equations


##9.2196x + 6.488y =0 -------(eq.1)##
and ##4.233x + 2.978y =0 ----(eq.2)##​

The Attempt at a Solution


I am multiplying ##(eq.1)## by ##4.233## and ##(eq.2)## by ##9.2196## but both the equations are vanishing. Some body please guide me.

Zulfi.

The two equations are equivalent. So, you just take the solution of either one.
 
And, it only determines the solution up to a constant multiplier, so you can for example arbitrarily set ##x=1## and then find ##y##.
 
Hi,
Thanks for your response. Answer is different in the slide. I have attached the slide. Please guide me.

Solving Decimal eq for Eigen vectors LDA vanishing_PicOfSlide.jpg
 

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  • Solving Decimal eq for Eigen vectors LDA vanishing_PicOfSlide.jpg
    Solving Decimal eq for Eigen vectors LDA vanishing_PicOfSlide.jpg
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In the solution for ##w_1##, the ratio of the components ##\frac{0.8178}{0.5755}## is the same as the ratio ##\frac{9.2196}{6.488}## in your system of equations. So it's the same answer but with different normalization, one where ##x^2 + y^2 = 1##.
 
Hi,
##lambda_2 =12.1983##
I am not able to get the correct answer.

##9.2196x + 6.488y = 12.1983x ##
##9.216x - 12.1983x = -6.488y ##

##\begin{bmatrix}x\\y\end {bmatrix} = \begin{bmatrix}2.7\\1\end{bmatrix}##

Somebody please guide me how can i get the correct answer?
Zulfi.
 
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