Evaluate ddx(1x2+1)\frac{d}{dx} \left( \frac{1}{x^2+1} \right)dxd(x2+11) at x=1x = 1x=1.
−1/2-1/2−1/2
1/21/21/2
−1/4-1/4−1/4
1/41/41/4