# Integral (need help getting started

1. Feb 15, 2009

### renob

1. The problem statement, all variables and given/known data
$$\int(x^4+2x^2+x+1)/(x^2+1)^x$$

3. The attempt at a solution
am I supposed to multiply out the denominator then do u sub?

2. Feb 15, 2009

### renob

nevermind i think its arctan

3. Feb 16, 2009

### HallsofIvy

Staff Emeritus
It isn't anything if the exponent on that denominator is really "x"! If it was supposed to be "2", I recommend dividing the fraction our so that you have a polynomial plus a "proper fraction" of the form $$\frac{ax+ b}{x^2+ 1}$$. That you divide into two parts: $$\frac{ax}{x^2+1}$$ and $$\frac{1}{x^2+ 1}$$. The first uses the simple substitution $$u= x^2+ 1$$ and the second is an arctan.