The Student Room Group


If you are familiar with cover up rule use that for a)
for b) use that answer and integrate
Reply 2
I've done the cover up rule that's the one I've always used with partial fractions but I keep getting B=-11/2
When i equate coefficients I get B=2 .
I don't get where it's gone wrong .
I'm fine with the integration:smile:


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Original post by livealittle
I've done the cover up rule that's the one I've always used with partial fractions but I keep getting B=-11/2
When i equate coefficients I get B=2 .
I don't get where it's gone wrong .
I'm fine with the integration:smile:


Posted from TSR Mobile

Type your working please.
Reply 4
Original post by keromedic
Type your working please.

Here,sorry it's not upright .my phone is acting up :frown:
(edited 9 years ago)
Reply 5
Don't know how you haven't seen this but when you let x=0, the A and C terms don't cancel out.

you end up with -4 = -2B
B=2
(edited 9 years ago)
you solve it via partial fraction form, change it into partial fraction form, then finally integrate via recognition you should get an answer in terms of natural logs, an aX term and some (a+bx)^n term
(edited 9 years ago)
Reply 7
Original post by Blobar
Don't know how you haven't seen this but when you let x=0, the A and C terms don't cancel out.

you end up with -4 = -2B
B=2


I know when X=0 A and C cancel out .How do you end up with -4 on the LHS?:frown:
Just realised.I made a mistake on my workings.it should be -2B not 2B Arrhhh-.-


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Reply 8
Original post by livealittle
I know when X=0 A and C cancel out .How do you end up with -4 on the LHS?:frown:
Just realised.I made a mistake on my workings.it should be -2B not 2B Arrhhh-.-


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But you are wrong when you say they cancel out because they dont. Sub in x=0. You get...

-11 = 4A - 2B + C

Sub in values you got for A and C and you'll get -4 = -2B after some rearranging.
Reply 9
Original post by Blobar
But you are wrong when you say they cancel out because they dont. Sub in x=0. You get...

-11 = 4A - 2B + C

Sub in values you got for A and C and you'll get -4 = -2B after some rearranging.


Sozzz -_-
I'm guessing I'll stick with equating coefficients then :|


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Reply 10
Original post by livealittle
Sozzz -_-
I'm guessing I'll stick with equating coefficients then :|


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And I'm sorry for trying to help by pointing out where you went wrong, oh wait.

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