Need help with algbra

[Zeek]

i have exams this week and i need help with some algebra that i dont know

[BFM_Kiwi]

Could you be more specific??

[McSkittles]

Could you be more specific??

Indeed.

[Liam]

Tell me it's polynomials right? Cmon, it's polynomials....Please! I'm good at polynomials  I also like to say polynomials....and trinomials, anyway, I'll see if I can help once you narrow it down. 





Polynomials

[jim360]

I thought the main point of algebra was that you didn't know some things anyway. THat's why they use "x" and "y" and call them "unknowns".

If you put up the specific problem there are plenty of people here who'll be able to help you.

[Zeek]

ok like i need help with % of change with sales/taxes and discounts

[jim360]

That's probably still not specific enough - what is the discount, and how much tax is there on what amount of money?

Having said that for a discount of d% you can say that given a starting price of x the new price is x-d*x/100, and similarly you can work what a t% tax rate comes to in real terms by saying that tax=t*y/100, where y is the amount of money that is being taxed.

If you're taxing on the discount price (what you pay after the discount) then in the second formula you would use y=x-d*x/100, and either add or subtract this result to y found earlier.

That's just about all I think there is to it.

As an example: if there's a 30% discount with VAT of 17.5% (the rate in the UK from January 2010) then for an item the shop would sell at £10 normally (excluding VAT) would cost the customer [17.5*(10-(30*10/100))/100]+[10-(30*10)/100]=£8.22 if VAT is worked out based on the discount price, or [17.5*10/100]+[10-(30*10)/100]=£8.75 if, as is probably more usual, VAT is worked out based on the normal selling price.

This is rather ugly, I grant you, but that's economics for you.

[Liam]

*blink* 

*Runs away to go do polynomials*

[jim360]

Well Liam, since you're so keen on Polynomials why don't you go prove the Fundamental Theorem of Algebra for me?

And then I'd love to know about Galois Representations...  

[Liam]

The Fundamental Theorem of Algebra says that for any polynomial f(x) with the degree n, where n>0, f must have at least one root, and not more than n roots alltogether. A root is a number x so that f(x) = 0.

Proof. Let n denote the degree of f . Without loss of generality, the assumption can be made that the leading coefficient of f is 1 . Thus, f(z)=zn+n−1m=0cmzm  .

Let R=1+n−1m=0cm  . Note that, by choice of R , whenever zR , f(z)=0 . Suppose that zR . Since R1 , zazb whenever 0ab . Hence, we have the following string of inequalities:

    n−1m=0cmzm    1+n−1m=0cmzmzn−1+n−1m=0cmzn−1Rzn−1zn

Since polynomials in z are entire, they are certainly analytic functions in the disk zR . Thus, Rouché's theorem can be applied to them. Since     n−1m=0cmzm    zn  for zR , Rouché's theorem yields that zn and f(z) have the same number of zeroes in the disk zR . Since zn has a single zero of multiplicity n at z=0 , which counts as n zeroes, f(z) must also have n zeroes counted according to multiplicity in the disk zR . By choice of R , it follows that f has exactly n zeroes in the complex plane.

 

And what about Galois Representation exactly would you wish to know, three60?

**Work Of: Wikipedia user and plantetmath.org**

[jim360]

It took a while for me to decipher that but I imagine that "0cmzm" means "sum from m=0 to some upper limit [probably n or n-2] of c_mz^m"? meanwhile, zn=zⁿ, where n and m are natural numbers such that m is less than or equal to m and n is non-zero.

The moral of this story is: don't just copy and paste from a maths document.

[Liam]

Haha, I was in way over my head 

Plus, I did give them credit    

   
**Work Of: Wikipedia user and plantetmath.org**

Hehe, anyway I bow down to you three60, you are the true master of maths. 

[Goalie]

I know what a large S in front of an expression means, and that's all I need to know about math.  And ANOVA, Simplex, differentials, random variables, curves, vectors, etc...

Hmm, now that I think about it, Industrial Engineering (my major) seems to encompass more types of mathematics than the other aspects of Engineering.  Electricals normally work with Calculus, Mechanicals (and many other types as well) with Physical math.  Industrials need to know Probability and Statistics, Linear Algebra, Calculus, and a few more that I have not learned about yet.  I find it very interesting how integrated math is to my career compared to other related fields.

That being said, math is one of my favorite subjects.  If it's high school algebra, I can most certainly help with that.

And what you just did 360 was business math.  But not like microeconomics doesn't use it.  I mean, I did take a course in that area last semester.

[Miser]

What percentage of math help threads go off topic after 5 posts?

[gamepanther]

The moral of this story is: don't just copy and paste from a maths document.

LOL that is halarious 60