How do you express (x^2 - 3x + 2) / (4x^3 + 11x^2)x23x+24x3+11x2 in partial fractions?

1 Answer
Dec 26, 2016

The answer is =(2/11)/x^2+(-41/121)/x+(285/121)/(4x+11)=211x2+41121x+2851214x+11

Explanation:

We start the decomposition into partial fractions

(x^2-3x+2)/(4x^3+11x^2)=(x^2-3x+2)/(x^2(4x+11))x23x+24x3+11x2=x23x+2x2(4x+11)

=A/x^2+B/x+C/(4x+11)=Ax2+Bx+C4x+11

=(A(4x+11)+Bx(4x+11)+Cx^2)/(x^2(4x+11))=A(4x+11)+Bx(4x+11)+Cx2x2(4x+11)

Therefore,

x^2-3x+2=A(4x+11)+Bx(4x+11)+Cx^2x23x+2=A(4x+11)+Bx(4x+11)+Cx2

Let, x=0x=0, =>, 2=11A2=11A, =>, A=2/11A=211

Coefficients of -3=4A+11B3=4A+11B

11B=-3-4A=-3-8/1111B=34A=3811

B=-41/121B=41121

Coefficients of x^2x2, 1=4B+C1=4B+C

C=1-4BC=14B

C=1+164/121C=1+164121

C=285/121C=285121

So,

(x^2-3x+2)/(4x^3+11x^2)=(2/11)/x^2+(-41/121)/x+(285/121)/(4x+11)x23x+24x3+11x2=211x2+41121x+2851214x+11