This discussion is closed.
Slice'N'Dice
Badges: 2
Rep:
?
#1
Report Thread starter 14 years ago
#1
Find the value of A, B & C.

x²/(x-2)(x-6) = A + B/(x-2) + C/(x-6)

x² = A(x-2)(x-6) + B(x-6) + C(x-2)

When x=2, B=-1

When x=6, C=9

How do I find A?
0
elpaw
Badges: 15
Rep:
?
#2
Report 14 years ago
#2
you have to expand the RHS, and set the coefficients equal.
0
manps
Badges: 0
Rep:
?
#3
Report 14 years ago
#3
when x = 1
using x²/(x-2)(x-6) = A + B/(x-2) + C/(x-6)
1/(-1)(-5) = a - 1/(-1) + 9/(-5)
a = 1

Alt method
when x = 1
using x² = A(x-2)(x-6) + B(x-6) + C(x-2)
1 = 5a +5 -9
5a = 5
a=1
0
Slice'N'Dice
Badges: 2
Rep:
?
#4
Report Thread starter 14 years ago
#4
Hmm, I get A=1.

Is that right?

Manps, How did you get A=3?
0
manps
Badges: 0
Rep:
?
#5
Report 14 years ago
#5
sorry i spotted the mistake and then changed it
0
Slice'N'Dice
Badges: 2
Rep:
?
#6
Report Thread starter 14 years ago
#6
Oh, alrighty.
0
X
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

University open days

  • Bournemouth University
    Midwifery Open Day at Portsmouth Campus Undergraduate
    Wed, 16 Oct '19
  • Teesside University
    All faculties open Undergraduate
    Wed, 16 Oct '19
  • University of the Arts London
    London College of Fashion – Cordwainers Footwear and Bags & Accessories Undergraduate
    Wed, 16 Oct '19

How has the start of this academic year been for you?

Loving it - gonna be a great year (110)
17.92%
It's just nice to be back! (166)
27.04%
Not great so far... (221)
35.99%
I want to drop out! (117)
19.06%

Watched Threads

View All