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    Okay i've got the equation  5x^3 + 14x^2 + 7x -2 I factorised this to make (5x-1) (x+2) (x+)
    So I got X = -2, -1 and 1/5
    I then sketched this like the crappy paint drawing below and got -2 < x <-1, x > 1/5 but the answer book says different and i'm confused
    any help? thanks

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    If the question asks where 5x^3+14x^2+7x-2 &gt; 0 then you're right. If it says &lt; 0 then you're wrong.
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    (Original post by nuodai)
    If the question asks where 5x^3+14x^2+7x-2 &gt; 0 then you're right. If it says &lt; 0 then you're wrong.
    It doesn't say either
    so would I just assume x=0 or...?
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    (Original post by emma363)
    It doesn't say either
    so would I just assume x=0 or...?
    What is the question, word for word? You've given ranges as an answer, but the ranges don't make any sense as an answer if the question hasn't asked you for a range. [But we can't see what the question is because you didn't post a question, you just posted a cubic function.]
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    (Original post by nuodai)
    What is the question, word for word? You've given ranges as an answer, but the ranges don't make any sense as an answer if the question hasn't asked you for a range. [But we can't see what the question is because you didn't post a question, you just posted a cubic function.]
    Oh just realised i'm looking at the wrong part of the question :facepalm: sorry for wasting your time :lol:

    It does say < 0 actually and I think I get it now :L
 
 
 
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Updated: September 30, 2010
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