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I never did get the hang of long division. It always looked just looked like a clusterf*** to me.
Friday, 08-Jun-12 17:26:50 UTC from web-
@ecmc You should try lattice multiplication some time. :P
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@ecmc Oh gosh I loved long division.
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@thelastgherkin Long division is useful to know, since calculators are not a guaranteed thing (common these days, yes, but not guaranteed). And it's pretty simple once you know how it works, anyway.
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@bitshift I find it funny that I only know long division. I never learned the short one.
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@thelastgherkin It's all fun and games until you have to start using it with quadratic equations.
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@ecmc OH MAN OH MAN I LOVED THOSE
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@ecmc We're just using our !fancymathematics.
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@bitshift We have a group for muddying the issue?
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@purplephish20 We certainly do. :3
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@ecmc Post a problem. I want to see if I can solve it!
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@thelastgherkin Not strictly a long division question, but it's the sort of s*** I have to deal with. (AND I SWEAR THIS PICTURE HAD BETTER NOT BE UPSIDE DOWN) http://ur1.ca/9gso3
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@ecmc Give me ten minutes! <3
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@ecmc (f -2) = 24
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@thelastgherkin for part a? f(-2)=0
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@ecmc You're right. I missed a multiplier. Damned if I'm stuck on part b now.
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@ecmc For instance, I did long division and got a remainder of -27.
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@thelastgherkin Yeah... part c is actually the only part of this question where you can use long division. I gave up on it even after looking at the mark scheme.
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@ecmc Either I've done the long division completely wrong here (possible) or the remainder is deliberate and Factor Theorem is completely non-applicable here.
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@ecmc Oh, duuuuuh. Give me a moment. I've had another idea.
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@ecmc OK, for part b you have to do f(3/2) resulting in 0.
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@thelastgherkin Yup!
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@ecmc Part c. We divide f(x) by (x+2), which is a factor as we know from part a. This gives us the expression (4x^2 - 8x +3). So we whack that into the expression given in the question to get (2x^2 + x - 6) / (4x^2 - 8x +3)(x+2). We can simplify it further than that! (2x^2 + x - 6) can be simplified into (2x - 3)(x + 2). (4x^2 - 8x + 3) can be simplified into (2x - 3)(2x -1). The expression becomes (2x - 3)(x + 2) / (2x - 3)(x + 2)(x + 2). We do this: (̶2̶x̶ ̶-̶ ̶3̶)̶(̶x̶ ̶+̶ ̶2̶)̶ / (̶2̶x̶ ̶-̶ ̶3̶)̶(̶x̶ ̶+̶ ̶2̶)̶(x + 2), giving us a final answer of 1/(x + 2).
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@thelastgherkin holy cupcakes. I have to look into this properly later O.O
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@thelastgherkin Lolol I graduated before that stuff was required learning. Canada ftw.
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@ecmc FSCK YEAH. If you have the final answer in the mark scheme, could you tell me if I'm right?
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@minti This wasn't required learning. I opted into it at college.
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@thelastgherkin Oh okay then. *salute* I'd like to learn it one day when I actually do go to college. xD
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@thelastgherkin It is correct. The mark scheme is useless for helping me to understand, but I think your explanation may legitimately help me :D
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@ecmc Radical! I'm useful! :D
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@minti Pssst... http://www.khanacademy.org/
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@bitshift o_o
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@minti It's seriously amazing. I was soooo rusty on maths after not using it for years, but that site's really helping me remember what I forgot, and even learn some things I never learned first time round (for example, our school never taught lattice multiplication, but I actually find it easier than regular long multiplication now I _do_ know it).
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@bitshift Friggin bookmarked. xD
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