(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Evaluate the integral when x > 0:

indefinite integral of ln(x^{2}+19x+84)dx

2. Relevant equations

I know I need to use some form of integration by parts: integral of u*dv=uv-(integral of(du*v))

3. The attempt at a solution

I began by making u=ln(x^{2}+19x+84) and dv=dx. Thus, (after u-substitution) du=(2x+19)/(x^{2}+19x+84) and v=x.

After putting that in the formula, we get x*ln(x^{2}+19x+84)-(integral of)((2x^{2}+19x)/(x^{2}+19x+84)). After simplifying that, I get:

x*ln(x^{2}+19x+84)-((x^{2}+19x+84)(4x+19)-(2x^{2}+19x)(2x+19))/((x^{2}+19x+84)^{2})

But according to the program I am using, that is the incorrect answer. Do you have any suggestions? Thanks.

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Integration of a natural log and polynomial

**Physics Forums | Science Articles, Homework Help, Discussion**