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Math Help - Find the difference quotient and simplify answer

  1. #1
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    Find the difference quotient and simplify answer

    f(x)=x^3-5x^2+x , f(x+h)-f(x)/h, h cannot = 0


    so far i got this

    3x^2h+3xh^2+h^3-10xh-5h^2+h/H

    i just need the correct answer so to see what i did or did not do.
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  2. #2
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    Now factorise h out of the top to get h(....) and then cancel the h's.
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  3. #3
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    ok now if i factor out h then i get

    h(3x^2+3xh+h^2-10x-5h)/h

    which = 3x^2+3xh+h^2-10x-5h

    for some reason this doesnt look right to me what did i do wrong????
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  4. #4
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    you've lost a "+1" at the end
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  5. #5
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    your not helping what is the answer?? im so stuck? i know i lost the +1 at the end. whats next?
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  6. #6
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    I actually think I am helping - I'm just not doing it for you ....there's a difference!

    What is the actual question...because you have "found the difference quotient and simplified the answer". Are you supposed to now go on and take the limit as h approaches 0?
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  7. #7
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    Quote Originally Posted by Debsta View Post
    I actually think I am helping - I'm just not doing it for you ....there's a difference!

    What is the actual question...because you have "found the difference quotient and simplified the answer". Are you supposed to now go on and take the limit as h approaches 0?
    im sorry you are helping but its just because im to freaking dumb to understand this stuff.
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  8. #8
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    Apology accepted . Don't put yourself down. What you have done so far is right (except for losing the +1 at the end, which is easy to do). Can you please quote the qusetion word for word?
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  9. #9
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    Quote Originally Posted by Debsta View Post
    Apology accepted . Don't put yourself down. What you have done so far is right (except for losing the +1 at the end, which is easy to do). Can you please quote the qusetion word for word?
    Find the difference quotient and simplify your answer.

    f(x)=x^3-5x^2+x, f(x+h)-f(x)/h, h cannot = 0


    i tried my best but the answer i got look so different from the examples in the book? or maybe the answer is right but just looks different?
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  10. #10
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    Can you show me the answer in the book - so I can see if it is just in a different form?
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  11. #11
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    Quote Originally Posted by Debsta View Post
    Can you show me the answer in the book - so I can see if it is just in a different form?
    the book does not give the answer to this problem because its and even number problems the book only gives odd number problems. but its ok i think this is correct though thank you so much.
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  12. #12
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    Glad to help!
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