## anonymous one year ago The partial fraction decomposition of a rational function is -3/(x+1) + (-2x) / (x^2+9). Evaluate the indefinite integral

1. anonymous

I did the evaluation and found the answer to be -log(x^2+9)-3log(x+1) but webwork says it's wrong

2. IrishBoy123

if you mean $$\large \int \frac{-3}{(x+1)} + \frac{-2x}{(x^2+9)} \ dx$$ looks right, if you added an integration constant maybe you need to manipulate a bit to please the software?

3. anonymous

Well the software returns an extra set of parentheses, making the answer$-(\log(x^2+9))-3\log(x+1)$ It seems like it should be right, but it just won't accept it

4. anonymous

@IrishBoy123

5. IrishBoy123

hi @RunawayGalaxy or you can write $$ln \frac{1}{x^2 + 9} + ln \frac {1}{(x+1)^3} + C$$ dunno, looks like a glitch, sure a human would be very happy with your work, webwork is presumably some kinda online thing....

6. anonymous

Yeah, it's the online homework program for my Calc class. Well thanks for the help, I'll try that, and email my professor if it doesn't work!

7. IrishBoy123

well, i stuffed it into Wolfram to eliminate "completely losing the plot" risk... and the Wolf agrees with you! http://www.wolframalpha.com/input/?i=+%5Cint+%5Cfrac%7B-3%7D%7B%28x%2B1%29%7D+%2B+%5Cfrac%7B-2x%7D%7B%28x%5E2%2B9%29%7D+++dx