\(\int \frac{x^{2}-1}{x^{4}+x^{2}+1}dx\) is equal to
Answer & explanation
Correct answer: option 3
\(\begin{aligned}\int \frac{x^{2}-1}{x^{4}+x^{2}+1}dx&=\int \frac{1-\frac{1}{x^{2}}}{\left(x+\frac{1}{x}\right)^{2}-1}dx\\ &=\int \frac{dt}{t^{2}-1} \text{ where }x+\frac{1}{x}=t\end{aligned}\)