help partial fraction decomp...

Discussion in 'General Discussions' started by ceneret0023, Feb 5, 2009.

  1. ceneret0023

    ceneret0023 Level III

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    ok so i understand it when it's basic stuff but im reviewing for my test and it gave me these

    x^(2)/(x^(2)+2x-15)

    and

    9/(x^(2)-9)

    and

    (x^(2)+2x)/(x^(3)-x^(2)+x-1)

    and one last one

    (3x^(3)+4x)/(x^(2)+1)^(2)

    and in the not partial deomp. section theres this one that has me stumped

    A misture of 6 gallons of chemical A, 8 gallons of chemical B, and 13 gallons of chemical C is required to kill a certain destructive crop insect. Commercial spray X contain 1, 2, and 2 parts, respectively, of these chemicals. Commercial spray Y contains only chemical C. Commercial spray Z contains chemicals A, B, C in equal amounts. How much of each type of commercial spray is needed to get the desired mixture?

    please can i have step by step instructions on how to do these? +rep to all who help me :)
     
  2. Zer0

    Zer0 Level IV

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    Always make sure you factor the denominator when doing partial fractions.

    For the first one, you'll notice that factoring won't work initially (the powers won't work out). So try polynomial long division first and then doing partial fractions on the remainder.

    For the second one, use factorization by grouping for the denominator.
    You should end up with:

    ( x^2 + 2x ) / ( ( x^2+1 )( x-1 ) )

    Then its just standard p.f. procedure

    The third one is standard p.f. procedure for repeated quadratic terms.

    Use this for basic p.f. help: http://jwbales.home.mindspring.com/prec ... rt7.6.html
     
  3. Ak*

    Ak* Level IV

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    Zer0 i think you are some kind of bio-computer hybrid... any question you tackle is like done in 2264 ms lol :p
     
  4. ceneret0023

    ceneret0023 Level III

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    thanks so much zero you'll get that rep as soon as i can give it to you again xD

    that's like amazing! my teacher said it all wierd and when we went through examples she went off on all these side notes and i got completely lost xD