Seigie B.

asked • 09/06/12

find the limit as it approaches -3 in the equation (6x+9)/x^4+6x^3+9x^2

lim-3=(6x+9)/(x4+6x3+9x2)

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Andrew G. answered • 09/07/12

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Parviz F. answered • 09/07/13

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Yusef H. answered • 10/08/12

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Andrew G.

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"...but a positive value as you approach from the right (positive infinity)."
 
This is incorrect.  The numerator ( 3(2x+3) ) is negative as x approaches -3 from either side, so the overall expression approaches negative infinity for both the left and right limit.  A limit that approaches infinity is not defined and therefore the limit does not exist.
 
 
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03/26/15

Walter B. answered • 09/14/12

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MIGUEL O.

l'Hôpital's rule also called Bernoulli's rule, uses derivatives to help evaluate limits involving indeterminate forms: and you can onely use it if lim f =lim g = 0 or +–8 and other conditions. However, this condition is not satisfied in this situation so you cannot use this rule. Sorry

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09/14/12

David F. answered • 09/06/12

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Heather P.

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Actually, you'd have to plug -3 into the function, but since you're trying to find the "limit as x->-3", you also have to see what the limit approaches from the left and right, and determine if it's an actual value (and the same from both sides).
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05/29/19

Jamie B. answered • 09/06/12

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