Re: HSC 2014 4U Marathon
\int{\dfrac{x^2}{x^6-1} dx} \\ \\ $let$ k=x^3 \\ \\ \frac{dk}{dx}=3x^2 \\ \\ \frac{dk}{3} = x^3 dx \\ \\ = \frac{1}{3}\int{\dfrac{dk}{k^2-1}} \\ \\ = \frac{1}{3}\int{\dfrac{dk}{(k-1)(k+1)}} \\ \\ = \frac{1}{3}\int[{\frac{1}{2(k-1)}-\frac{1}{2(k+1)}]dk} \\ \\ =...