View Profile Lingqi
 
Reply Wed 1 Oct, 2008 03:46 pm
Express (x^2+23)/((x+1)^3(x-2)) in partial fraction
 
View Profile Ragman
 
  1  
Reply Wed 1 Oct, 2008 04:31 pm
Let me guess -- you want us to do totally your homework for you without showing anything you have done to try and solve ther problem on your own? Is that about right?
View Profile Lingqi
 
  1  
Reply Thu 2 Oct, 2008 06:17 am
No, its not that i hv done it but i'm lazy to type my working coz 2 long..My working is wrong so i jz wan 2 knw anybody knw alternate method to solve it..Jz doing some research..If got new method i learn more..If nt nevermind..Anyway my teacher wil explain it..Dont u think by doing this u might find easier ways to solve this questions than ur tcer method..I'm juz doing comparing..No offence..Sorry if i hv say o done anything wrng
0 Replies
 
  1  
Reply Thu 2 Oct, 2008 09:07 am
Lingqi wrote:

Express (x^2+23)/((x+1)^3(x-2)) in partial fraction

In general, a fraction with n linear factors of x+1 in the denominator can be decomposed as follows:

A1/(x + 1) + A2/(x+1)^2 +...+ An/(x+1)^n
0 Replies
 
View Profile Miller
 
  1  
Reply Thu 2 Oct, 2008 09:29 am
Lingqi wrote:

Express (x^2+23)/((x+1)^3(x-2)) in partial fraction


How come you didn't say "Please"?
0 Replies
 
View Profile Lingqi
 
  1  
Reply Fri 3 Oct, 2008 05:46 am
Ok please anybody o miller can you all have a look what i have done..(x^2+23)/((x+1)^3(x-2))=a/(x+1)^3+ b/(x+1)^2 + c/(x+1) + d/(x-2)

=a(x-2) +b(x+1)(x-2)+ c(x+1)^2(x-2)+ d(x+1)^3

=(c+d)x^3+ (b+3d)x + (a-b-3c+3d)x^2 + (-2a-2b-2c+d)

comparing coefficient:

c+d=0 ->eqn 1, a-b-3c+3d=0 ->eqn 2, -2a-2b-2c+d=23 ->eqn 3, b+3d=1 ->eqn 4

put eqn 2=eqn 3: 3a+b-c+2d-23=0 ->eqn 5

put eqn 1=eqn 4: c+d= b+3d-1

-2d+ c- b+ 1=0 ->eqn 6

eqn 5 + eqn 6:

3a-22=0

3a=22

a=(22)/3

put a into eqn 5, b- c+ 2d-1=0

put eqn 1 into eqn 5 where c= -d, b-(-d)+2d-1=0

b+3d=1

please anybody know how to continue the rest & where i got wrong because the real answer is 1/(x-2) - 1/(x+1) -2/(x+1)^2 -8/(x+1)^3
0 Replies
 
 

Related Topics

Probability Question. - Discussion by babemomlover
Population growth formula - Discussion by Ellinas
Algebraic Equation - Question by parini13
Set theory and Logic - Question by Premiere71
graph the trig function - Question by sara313
what is the range?median?average - Question by nicolle
1=-1 - Question by aman
coin tossing - Question by zyrus64
Calculus problem - Question by aperson
 
  1. able2know
  2. » Partial fraction
Copyright © 2009 Horizontal Verticals :: Page generated in 0.36 seconds on 11/08/2009 at 03:08:16 Top End