The derivative of 1/f(x)1/f(x)1/f(x) is:
−f′(x)/[f(x)]2-f'(x) / [f(x)]^2−f′(x)/[f(x)]2
1/f′(x)1 / f'(x)1/f′(x)
f′(x)f'(x)f′(x)
ln(f(x))\ln(f(x))ln(f(x))