Find the derivative of f(x)=xarctan(x)f(x) = x \arctan(x)f(x)=xarctan(x).
arctan(x)+x1+x2\arctan(x) + \frac{x}{1+x^2}arctan(x)+1+x2x
arctan(x)+x21+x2\arctan(x) + \frac{x^2}{1+x^2}arctan(x)+1+x2x2
11+x2+x\frac{1}{1+x^2} + x1+x21+x
arctan(x)−x1+x2\arctan(x) - \frac{x}{1+x^2}arctan(x)−1+x2x