Help Jedi with His Algebra

Nobody in your thread seems to have the slightest clue what synthetic division actually is...

Come now, I just thought that since Mr. Jedi is supposed to be doing his homework on his own that an exhaustive typing job such as yours was unwarranted. 

I don't know if synthetic division can be used for dividing roots larger than degree 1 though...  I suppose I could try some time.

I bet you'd have to do it two time with the same root if its order was larger than 1. Although I can't be sure because I never use this division method.
And you're right it might not be as slow as I said it in my last post it's just that... I don't use it.

I never did thank you guys.

Thank you!

I just finished a test today, &  there was a problem that involved using the Rational Zero Test of Polynomials !

And I tried plugging in every combination of fractions I was given into x, before doing synthetic division (I would use that to verify), but none of them worked!




I won't know until Monday to see what my score was. I hate this!

I wanna know what I got!

I just received my last test, & boy am I steamed:



Apparently I didn't use Gaussian Elimination, & there's a portion that's circled where I made the 'mistake.'  I received only half credit.  I obviously disputed this.  Because the first 'x' in the first row equation should remain a '1,' I was penalized for multiplying the entire thing by '3' (because I didn't want to work with fractions).  Otherwise, everything else is correct, & I found the correct answer.



It may be hard to see this, but dividing everything by '7' seems to be my mistake.  #!@%#@$%*&^&#$%^@#$!%#$^!$

But then I saw that I forgot to write both equations after every step, so I can understand this one.  By the way, I got the correct answer, albeit, with much less trouble than the instructor when he demonstrated it.

Wow, that's a perfect example of how not to do Gaussian elimination, way to go!

3	-5	-14	-4
1	-2	1	5
2	-6	37	-10

=>

0	1	-17	-19
1	-2	1	5
0	-2	35	-20

=>

0	1	-17	-19
1	0	-33	-33
0	0	1	-58

Basically done. You can resubstitute or do one more pivot, your choice. You'd need a calculator or be really bright either way.

0	1	0	-1005
1	0	0	-1947
0	0	1	-58

Done. Net time to do it: 2 mins. How many questions were there?

The way you solved it is taught in eigth grade in Germany, no offense intended. Just use the Gauss-Jordan method like it was originally designed using a pivot element and you're all set, even for bigger systems and multiple solutions. Don't do that fraction stuff and writing down all the x, y, z crap. Concentrate on the important parts: the coefficients that actually determine the system. I seriously hope this is beginner's math or math for art students...

Also, the teacher was probably born on 10 May 1947 and was 58 years old when he designed the question in 2005.

cYa,

Tauwasser

Don't do that fraction stuff and writing down all the x, y, z crap.

As the first question establishes, they're evidently quite insistent on things being written down in a particular way.

...Say, does that table code work on phpBB and vBulletin, or is it strictly an SMF thing?  I've never seen that before.

Just use the Gauss-Jordan method

Gauss-Jordan was not an option here.  There was another problem just for that.  Believe me, I didn't prefer Gaussian Elimination.

I seriously hope this is beginner's math or math for art students...

This is college algebra.  And simply saying 'no offense' doesn't alleviate anything you say.  It still sounds like you're trying to be offensive.

Gauss-Jordan was not an option here.  There was another problem just for that.  Believe me, I didn't prefer Gaussian Elimination.

Gauss is Gauss-Jordan! The only difference is that the pivot's row (within the current sub-matrix) is only added to one less row each step into the algorithm instead of being added all other rows in all steps! Even though the Gauss algorithm was there first, there is really not much difference.

I would also like to point out that you did not perform the Gauss algorithm but the Gauss-Jordan algorithm in the first place, so don't shout at me for that! If you had used the Gauss algorithm, you would have substituted your anser for z in (3R_2 + R_1) or the one below that on the left hand side and worked from there in any of the original three equations by substituting y and z to get x. Instead, you performed further steps to get the identity of each variable in their own right, which is what the last Gauss-Jordan block in my exemplary solution does ― and which you performed as well in the lower right-hand corner. You should have stopped at the point above where I wrote basically done and substituted the known variables back for performing the original Gauss algorithm.

This is college algebra.  And simply saying 'no offense' doesn't alleviate anything you say.  It still sounds like you're trying to be offensive.

I know, but I notice a lot of Americans really like to say no offense for no particular reason and without using particularly kind words preceding or following that statement. So naturally, I thought I'd try it But just for the record: I think your math is too easy and yet you still struggle with it. This is aggravating to me, because back here in good ol' Germany, we don't exactly get our degrees handed to us on a silver platter. My US high school experience also adds to that feeling, because I know that excellent and well-prepared math courses do exist in the US, yet a lot of students take three consecutive years of Geometry class where they must endure the excruciating pains of basic shapes... 

cYa,

Tauwasser

I never did tell you guys how I did.

I got a B.

Thanks all!