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    Here is the question I am doing:

    Name:  lappar.JPG
Views: 92
Size:  9.9 KB

    Here are my calculations so far:

    Name:  IMG_1524.JPG
Views: 80
Size:  229.9 KB

    I know I am going wrong somewhere but I don't know where. When solving the last two equations (shown) simultaneously I am getting different answers for C.

    Any help on this is hugely appreciated thank you!
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    (Original post by Kaya_01)
    Here is the question I am doing:

    Name:  lappar.JPG
Views: 92
Size:  9.9 KB

    Here are my calculations so far:

    Name:  IMG_1524.JPG
Views: 80
Size:  229.9 KB

    I know I am going wrong somewhere but I don't know where. When solving the last two equations (shown) simultaneously I am getting different answers for C.

    Any help on this is hugely appreciated thank you!
    Because s^2 + 1 is a quadratic factor, it needs a numerator like Bs + C. If you think about it, there's no point in having one term with numerator B and another with numerator C over the same factor, because you could just combine them into one constant D = B + C
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    (Original post by Kaya_01)
    Here is the question I am doing:

    Name:  lappar.JPG
Views: 92
Size:  9.9 KB

    Here are my calculations so far:

    Name:  IMG_1524.JPG
Views: 80
Size:  229.9 KB

    I know I am going wrong somewhere but I don't know where. When solving the last two equations (shown) simultaneously I am getting different answers for C.

    Any help on this is hugely appreciated thank you!
    Just split the first term into two separate fractions.
    which should give you  \frac{1}{S^2}-\frac{1}{S^2+1} Then separate the  \frac{s-2}{s^2+1} into \frac{s}{s^2+1}-\frac{2}{s^2+1} you should then be able to see how to get the required result.
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    (Original post by davros)
    Because s^2 + 1 is a quadratic factor, it needs a numerator like Bs + C. If you think about it, there's no point in having one term with numerator B and another with numerator C over the same factor, because you could just combine them into one constant D = B + C

    would I then equate it to A/s^2 + Bs+c/(s^2+1) ? What about the third denominator and what about the LHS?

    thank you
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    (Original post by Kaya_01)
    would I then equate it to A/s^2 + Bs+c/(s^2+1) ? What about the third denominator and what about the LHS?

    thank you
    The only term which requires partial fractions is the: \dfrac{1}{s^2(s^2+1)}
    So let:
    \dfrac{1}{s^2(s^2+1)}=\dfrac{A}{  s}+\dfrac{B}{s^2}+\dfrac{Cs+D}{s  ^2+1}
    The \dfrac{s-2}{s^2+1} in the LHS can be accounted for after your partial fractions.
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    (Original post by Kaya_01)
    would I then equate it to A/s^2 + Bs+c/(s^2+1) ? What about the third denominator and what about the LHS?

    thank you
    There isn't a "third" denominator - if you look at what they've done, they've just split out the bit over (s^2 + 1) into 2 separate fractions!
 
 
 
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