X^3-1/X+2

This says X to the power of 3, subtract 1, divided by, X plus 2.

Thanks I coudn't even start this question because all the other question had three or more top numbers like X^3+2X^2-13X+10.

I need this help.

Thanks for the help....(Nod)

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- Jul 20th 2009, 02:04 AMAwsom Guysolve Polynominal question - easy
X^3-1/X+2

This says X to the power of 3, subtract 1, divided by, X plus 2.

Thanks I coudn't even start this question because all the other question had three or more top numbers like X^3+2X^2-13X+10.

I need this help.

Thanks for the help....(Nod) - Jul 20th 2009, 02:11 AMmr fantastic
- Jul 22nd 2009, 03:36 PMkanu999
Hi

Well are you trying to solve for X when that equation is equal to ZERO?

e.g. ((X^3)-1)/(X+2) = 0

If so then all you need to do is solve for (X^3)-1 = 0, because if the top line is zero then the whole fraction is zero.

Therefore solving that equation will give an answer of X=1.

Also there are two more solutions (it is a cubic).In order to get those you need to do long division on (X^3)-1 with (X-1), which will then give an equation of ((X^2)-X+1). And when you solve this for zero you will get two complex roots 0.5+0.86i and 0.5-0.86i

Hope this helps - Jul 22nd 2009, 11:49 PMOpalg
If this is a question about how to do polynomial division, you should think of the numerator as being $\displaystyle x^3 + 0x^2 + 0x - 1$. Then it will have "three or more top numbers" (even though some of them are zero), and you can divide it by x+2 in just the same way as you would if it was something like "$\displaystyle X^3+2X^2-13X+10$".