You are making this a lot harder than it needs to be. Just use the distributive property to expand it out into a polynomial. That is:
$$(x^2 + 1)(x + 1)=x^3+x^2+x+1$$
If you are masochist, however, integration by parts works too. :)
You are making this a lot harder than it needs to be. Just use the distributive property to expand it out into a polynomial. That is:
$$(x^2 + 1)(x + 1)=x^3+x^2+x+1$$
If you are masochist, however, integration by parts works too. :)