partial fractions quadratic term
DESCRIPTION
Partial fractions with one quadratic term which does not factorise on the denominatorTRANSCRIPT
Partial FractionsQuadratic term on the denominator
Expressions with ax2 + bx + c in the denominator decompose to terms of the form:
2
Ax B
ax bx c
2
2( 4)( 4)
x x
x x
To express
as partial fractions.
2( 4) 4
A Bx C
x x
Express as individual fractions with the factors on the denominator:
2
2
( 4) ( 4) ( 4)
( 4)( 4)
A x Bx x C x
x x
Express with a common denominator:
2
2
( ) (4 ) 4( )
( 4)( 4)
A B x B C x A C
x x
Using Method OneEquating Coefficients
Equating coefficients of x2 :
A+B = 1
Equating the coefficients of x:
-(4B-C) = 1
Equating the constant terms:
4(A-C) = 0
Using a GC or otherwise:
A = 1, B= 0, C= 1
2
2 2
1 1
( 4)( 4) ( 4) ( 4)
x x
x x x x
Hence: