Linear Algebra Help

Hey so I saw some people post a couple statics questions here before and I am not a member of a math forum sooooo

Anyone here able to explain this sort of problem? I did not screenshot the actual homework problem but rather a practice homework. I am a bit unsure how to go about it, anyone know?

Listen pal, the only reason that I passed math in high school was so that I'd never have to look at it again...

That deceptive title must have lured you in to look right?

My math teacher pissed me off in 7th grade, been bustn rocks eversince.

I know yall were absolutely dying to know the answer.
[2,2,0,0;-4,4,0,0;0,0,-4,4;0,0,2,2]

that is a foreign language to me ... when I was taking HS math and later Jr college algebra the word matrix never showed up .... ever ... don't have any idea what that is

The Curmudgeonling knows exactly what it is and how to work it. She's a damn sight more math smart than her ol' pop.

I forgot how to do the matrices like that. You will too.

Isn't that part of diff equations? That's 2 math classes ahead of me. I have almost 1/4th of an engineering degree.

Anti-stance wrote: I forgot how to do the matrices like that. You will too.

Quoted for truth :)

When I took Algebra in high school (1959) I don't think those kind of problems existed.

fritzsch wrote: Hey so I saw some people post a couple statics questions here before and I am not a member of a math forum sooooo Anyone here able to explain this sort of problem? I did not screenshot the actual homework problem but rather a practice homework. I am a bit unsure how to go about it, anyone know?

Ok.

The matrix on the far left contains the variables. The matrix in the middle contains the coefficients. The matrix on the right has the results.

First row of the left matrix times the first column of the middle matrix gives the first number in the first row, first column of the right matrix. It rattles on from there and you'll eventually get lost when dealing with four or more columns or rows if you do it by hand.

So I'll spot you the first line of the answer.

2x + 2y = 0

and in the form the problem wants it it's

2 2 0 0

because you're multiplying by the column of variables x y z w.

Even though I used wiki and some diff eq I failed in 02, multiply your line by your row to make out your equations.

So for your example problem, you take your first line and multiply with your first row which would look like this:

2x + 2y = 0

Second line, I THINK, will be:

-4y + 4x = -2

and so forth. Then it become simple algebra to solve for one of the variables to solve for the other.

HTH.

I keep wanting to have all the advanced math I learned in school immediately available for the applications in pondering tires, chassis, etc, though I have a lot to learn there before I could really apply it.

But, it's mostly gone. I graduated in 2005, and used linear algebra exactly once outside of the class where it was taught, while writing MultiTherm to do what MegaTherm did for Windows on other platforms (work out a Megsquirt temperature lookup table for alternative sensors). Even then, I pretty much "cookbooked" programming the linear algebra part of the software.

Hal wrote: When I took Algebra in high school (1959) I don't think those kind of problems existed.

Or in 1976 when I graduated. Damn new math.

People think of math as being fairly straightforward. Heck, even calculus made sense to me after a while. But there are some things that pass for math that I cannot grasp. I was dazed by a class called Discrete Mathematics. Pretty sure my test average was below 50. Shortly after that I transferred into Business and started making dean's list.

Duuuuude, sorry. I studied Circular Algebra.

thought this was appropriate ;-)... not the one I was looking for but works all the same

I have a degree in applied math (1986), and took every linear algebra class offered because a brilliant professor tought them (among other classes). And I don't remember ever seeing a set up like that. So I'm going with the,

"I forgot how to do the matrices like that. You will too." answer.

I begin to wonder of people are think up pointless new ways of doing things that don't need fixing.

spin_out wrote: I begin to wonder of people are think up pointless new ways of doing things that don't need fixing.

Welcome to Engineering!!!

chaparral wrote:

fritzsch wrote: Hey so I saw some people post a couple statics questions here before and I am not a member of a math forum sooooo Anyone here able to explain this sort of problem? I did not screenshot the actual homework problem but rather a practice homework. I am a bit unsure how to go about it, anyone know?

Ok. The matrix on the far left contains the variables. The matrix in the middle contains the coefficients. The matrix on the right has the results. First row of the left matrix times the first column of the middle matrix gives the first number in the first row, first column of the right matrix. It rattles on from there and you'll eventually get lost when dealing with four or more columns or rows if you do it by hand. So I'll spot you the first line of the answer. 2x + 2y = 0 and in the form the problem wants it it's 2 2 0 0 because you're multiplying by the column of variables x y z w.

and this accomplishes WHAT ?

graduated HS 1967 ... this stuff didn't exist then .. there's bound to be an easier way to reach the same answer

wbjones wrote: graduated HS 1967 ... this stuff didn't exist then .. there's bound to be an easier way to reach the same answer

This is why I wish I had better command of all the math I've seen; This might be the easier way.

I just graduated majoring in Math in May, but I haven't seen a set up like that... Of course, I absolutely hated linear and only took one class of it.

I really enjoyed my discrete classes.