How do you find the integral of (x^3 + 1) lnxdx?

1 Answer
Apr 30, 2018

(x^4/4+x)(In x)-x^4/16+x+C

Explanation:

Let u= In x
And dv=x^3+1 SO v=(x^4/4+x)

Integration by parts is given by = vu-intv du

int (x^3+1) In x dx = (x^4/4+x)(In x)-int (x)(x^3/4+1)times1/x dx

=(x^4/4+x)(In x)-int (x^3/4+1) dx

=(x^4/4+x)(In x)-x^4/16+x+C