Factoring to Find the LimitDate: 11/5/95 at 23:2:15 From: John Florance Subject: limits... Hi Doc... 3 lim x + 8 x -> -2 ----------- = ??? x + 2 i.e., how to factor the numerator? John Date: 11/6/95 at 11:7:0 From: Doctor Ethan Subject: Re: limits... Hey John, Here is the deal. We have to factor the top into two factors so that we can cancel with the bottom. Fortunately there is a standard rule for factoring things that are in the form of a^3 + b^3 If I tell you the first factor do you think you can figure out the second? The first looks like a + b or in the case of this problem x + 2. So what would the second factor have to be in order to work out? I will tell you that it is a trinomial of highest power two. So you need to figure out: (x + 2)(what goes here) = (x^3 + 8) Have fun. I think that you can figure it out. If you can't, write back and we will help you. -Doctor Ethan, The Geometry Forum |
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