Homework

[Neb]

Okay, I tried doing the two things. I'll post my results, please tell me if they're right or wrong, for (X-1):

X^3-5X^2+5X+9+(-10/(X-1))

And for (X+1):

X^3+3X^2-3X-7+(6/(X+1))

It's horribly wrong, isn't it?

[LennonCook]

x^4+4x^3-4x-1=(x+1)(x^3+3x^2-3x-1)=(x-1)(x^3+5x^2+5x+1)

That help at all ?? [img]smile.gif[/img]

[Neb]

Blech, I miscalculated something? Damn, I should have known.... *sigh* Guess this homework isn't getting handed in today. I need more time to work on it.... *slams face into nearest hard surface*

[Night Stalker]

Originally posted by Neb: Okay, I tried doing the two things. I'll post my results, please tell me if they're right or wrong, for (X-1): X^3-5X^2+5X+9+(-10/(X-1)) And for (X+1): X^3+3X^2-3X-7+(6/(X+1)) It's horribly wrong, isn't it?

Very close. Neither div has a remainder. You forgot the 0x^2 term in both cases.

you need to div your term {(x-1)|(x+1)} into:
x^4+4x^3+0x^2-4x-1

Whenever doing polynomial div and there is a missing term (x^2 in this case) you need to add a 0 filler. Start from the highest exp and count down left to right, there should be no break in numbers. ex: x^5 + x^3 + 1 needs to be rewritten as x^5+0x^4+x^3+0x^2+0x+1

Keep going you almost have it!!!

You also have a sign error in your x-1 div.

[Neb]

Thanks Stalker [img]smile.gif[/img] I always make mistakes with those bloody signs....

[Suzaku]

So if u havn't understood already (can't tell):

-Factor those ugly suckers into understandable components.
-Border Values? pleaz clarify.
-Asymptotes are simply values that are nhon-permissible, usually to reciprocal functions. Like f(x)=1/(x+1) where x=-1 is an asymptote line.

Dig?

[Neb]

I know what Asymptotes are, but what I have some problems with are doing things with them [img]tongue.gif[/img]

[Neb]

Blast, I can't get either of the two equations to end without a remainder. Could someone possible show me how they'd calculate them? I'm having a bit of trouble with this though I suspect that it's just my own stupidity.

[Donut]

Originally posted by Neb: Okay, I need a bit of help with some homework. Maths homework to be precise. What I need help with is: Polynomic Division Border Values and Asymptotes My first problem is with PD. (X^4+4X^3-4X-1)/(X-1) and (X^4+4X^3-4X-1)/(X+1) What effect will the difference between dividing with (X-1) and (X+1) have?

Is the answer 'red'?

[andrewas]

Originally posted by Neb: Blast, I can't get either of the two equations to end without a remainder. Could someone possible show me how they'd calculate them? I'm having a bit of trouble with this though I suspect that it's just my own stupidity.

My answer to the first one.

           

               x^3  +  5x^2  + 5x  +  1

    -----------------------------------

x-1 | x^4  +  4x^3  +  0x^2  - 4x  -  1

    --------------

      x^4  +   x^3

      0    +  5x^3   + 0x^2  - 4x  -  1

              5x^3   - 5x^2

              -------------

               0     + 5x^2  - 4x  -  1

                       5x^2  - 5x

                       -----------

                        0    +  x  -  1

                                x  -  1

                                --------

                                0  +  0



              

That should be right for the first one. For the second one your on your own though. I mean it. The notation is as taught to me in school a long time ago. Different teachers have different layouts, but you should be able to de-tangle it.

Edit - I was also gonna say - be careful of the signs. -4 - (-5) =1. Subtracting a negative = adding.

[ 09-16-2002, 12:44 PM: Message edited by: andrewas ]