I thought i'de do this for the math geeks in here. i love math, and since im doing a friends internet course for him, i thought ide just rip a problem out and see u guys can do it. im up to the level of pre-calculus, not in the big leagues yet, but the average informed person can probably do these.
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i know the answer to this one, but can u find it?

Find all the real RATIONAL zero's in this equation. (In other words, find how many time "x" crosses the "x" axis on a graph.)(or find all the real solutions of "x" that makes the equation = to zero. youll get a PRIZE!!!

x^3 - 4x^2 + x + 6 = 0

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SOLVED : y = 2(+/-)square root of 14

y = y^2 -3y -10

i have no clue how to find y now, even after factoring it.

y = (y-5)(y+2)

original problem is.

(y+2)/y = 1/y-5

WHAT THE IS Y!!!!????

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Last edited by Krypton on Dec-22-2005 at 01:27

set everything equal to zero.

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quote:

Originally posted by ierxium set everything equal to zero.

tried that, doesnt work.

y = y^2-3y-10

y-y = (y^2-3y-10)-y

0 = y^2-4y-10

if i use the quadratic equation, i get very ugly numbers that i know arent right. i dont think i can use the zero property anyways.

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quote:

Originally posted by ::TranceVanDyk:: ive been working this one problem, and have worked it all the way to this point. y = y^2 -3y -10 i have no clue how to find y now, even after factoring it. y = (y-5)(y+2) original problem is. (y+2)/y = 1/y-5 WHAT THE IS Y!!!!???? edit:: ACTUALLY ITS precalculus, not all the way to the big leagues yet

y^2 - 3y - 10 - y = 0
y^2 - 4y - 10 = 0
(y-5)(y+1) = 0



y=5 y=-1

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quote:

Originally posted by ierxium y^2 - 3y - 10 - y = 0 y^2 - 4y - 10 = 0 (y-5)(y+1) = 0 y=5 y=-1

That's incorrect. If you use F.O.I.L. to check your answer you will get y^2 - 4y - 5.

Trance van Dyk just start from here:
y^2 - 4y - 10 = 0
and use the quadratic formula because that is impossible to factor using regular methods.

quote:

Originally posted by ierxium y^2 - 3y - 10 - y = 0 y^2 - 4y - 10 = 0 (y-5)(y+1) = 0 y=5 y=-1

lol, nope, u factored it wrong.

what u factored equals y^2-4y-5. c = 10, no 5. this is damn hard.

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set everything equal to davedresden

quote:

Originally posted by stevieboy32808 That's incorrect. If you use F.O.I.L. to check your answer you will get y^2 - 4y - 5.

hence the

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wait this is in a calc class? wtf?

yep, stevieboy is right do what he says

quote:

Originally posted by stevieboy32808 That's incorrect. If you use F.O.I.L. to check your answer you will get y^2 - 4y - 5. Trance van Dyk just start from here: y^2 - 4y - 10 = 0 and use the quadratic formula because that is impossible to factor using regular methods.

i guess my answer's going to be y = 2 (+-)square root of 14

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quote:

Originally posted by Demoted Oh, I thought that was your "I just got the answer right as I sat on my wet fart." face.

Could be.

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