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February 18, 2013

## How do you find eigenvectors manually?

This is what I have so far:

x1+x2 = 0
3×1+x2 = 0

Make it into a matrix A and get det[A-lamda] where lamda values = eigenvalues
plug eigenvalues back into matrix A-lamda

Then what? How do you find eigenvectors x1 and x2? Do you reduce echleon and that’s your answer? Is it difficult to do?

It looks like you know how to find eigenvalues. By taking the determinant of |A-I*lamda| = 0

Once you have the eigenvalues, you use those values in the matrix A-I*(lamda) = 0, arrange the matrix into epsilon form and you’ll get a row of zeros.

From that row, get an arbitrary value for x2 or x1, say x2 = 2 (any number), and use this to find x1 on row 1. Your eigenvector is then vector:

V =
[c]
[d]

Where d is your arbitrary value for x2 and x1 is what you solved for in row 1 using x2.

There is an infinite number of vectors that can satisfy the eigenvector, but you only choose one of those infinite vectors as your eigenvector representative. If you’re solving a differential equation, the constant that multiplies the solution takes care of the rest.

*edit to add: if you have two eigenvalues, you’ll have two eigenvectors for each respective value.

## Where Can I Find 5″X3″X1″ Shipping Boxes In Houston, Texas?

I am looking for shipping boxes that are 5″X3″X1” in the Houston, Texas area. I have found Uline online but after paying the shipping fees on these small boxes, the prices are too high to pass on to my customers, or to eat the cost myself. I am looking for a place where I can pick up boxes in this size in bulk.
I should have also mentioned this is for first class shipping, not priority mail.

Http://www.usps.com/

## How do you find slope in a position vs. time graph?

Is it x2-x1 divided by y2-y1? Or is it something different?

It’s a normal slope equation: m = (y2 – y1) / (x2 – x1)

## How do you soften a thick block of wood before cutting it?

2”x1” block of wood. I want to soften it. How do i do that?