Which technique is best to solve ∫dxx4+x2+1\int \frac{dx}{x^4+x^2+1}∫x4+x2+1dx?
Partial fractions after factoring (x2+1)2−x2(x^2+1)^2 - x^2(x2+1)2−x2
Substitution u=x2u = x^2u=x2
Integration by parts
Trigonometric substitution x=tanθx = \tan \thetax=tanθ