I am trying to design an integration question which involves three methods, namely substitution, integration by part and partial fraction.
However, I couldn't design such a question. The best I can do involves at most $2$ methods, but not $3$. For example,
$$\int x^8 e^{x^3} \ dx$$
The integral above involves only substitution $(u=x^3)$ and by part, but not partial fraction.
It would be good if someone can come out a question involving three methods.
Answer
An example could be
$$
\int\frac{x^2\ln x}{\left(1+x^3\right)^2}\:dx.
$$
By the change of variable $u=x^3$, $du=3x^2dx$, one gets
$$
\int\frac{x^2\ln x}{\left(1+x^3\right)^2}\:dx=\frac19\int\frac{\ln u}{\left(1+u\right)^2}\:du,
$$ then one may use an integration by parts
$$
\frac19\int\frac{\ln u}{\left(1+u\right)^2}\:du=-\frac{\ln u}{9\left(1+u\right)}+\frac19\int\frac1{u\left(1+u\right)}\:du
$$and conclude by partial fraction decomposition.
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