Partial Fractions

tangur

Hi I need some help getting started with this integral

[tex]\int \frac {x^2+5x+2}{{x^4+x^2+1}}dx[/tex]

Thanks in advance

Astronuc

Try working the denominator -

[tex]x^4+x^2+1 = (x^4+2x^2+1)-x^2 [/tex]

then use the identity

[tex]x^2-y^2 = (x+y)(x-y)[/tex]

Astronuc

You were on the right track.

To eliminate the [tex]x^3[/tex] term, C=-A.

Then find 3 equations in three unknowns A, B, D.