Find f′(x)f'(x)f′(x) for f(x)=x2arctanxf(x) = x^2 \arctan xf(x)=x2arctanx.
2xarctanx+x21+x22x\arctan x + \frac{x^2}{1+x^2}2xarctanx+1+x2x2
2x1+x2\frac{2x}{1+x^2}1+x22x
2xarctanx+x22x\arctan x + x^22xarctanx+x2
x2+2x(1+x2)arctanxx^2 + 2x(1+x^2)\arctan xx2+2x(1+x2)arctanx