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January 20, 2017
Posted by **ibk** on Saturday, March 10, 2012 at 8:44am.

- science -
**drwls**, Saturday, March 10, 2012 at 10:13amDo you mean

f(x)= 1/sqrt(x^2+1) = (x^2)+1)^-1/2?

The derivative would be

f'(x) = (-1/2)(2x)/(x^2 +1)^(3/2)

= -x/(x^2 +1)^(3/2)

The "chain rule" was used.

df/dx = df/du*du/dx

with u(x) = u^2 +1 and f(u) = u^-1/2