# Math Help - Right Hand Derivative and Left Hand Derivative

1. ## Right Hand Derivative and Left Hand Derivative

If $f(x)=\left(\frac{1-x}{1+x}\right)^{\frac{1}{x}}$; $x\neq 0$

and $f(0)=\frac{1}{e^2}$

Evaluate $f_{+}'(0)$ and $f_{-}'(0)$

2. The standard definition of a one-sided derivative of f at 0 requires f to have a value at 0, which your f does not. What definition of one-sided derivative are you using? Do you mean the value that the derivative function approaches at 0 (ie., $f_{+}'(0) = \lim_{x\rightarrow 0^+} f'(x)$)?

3. Thanks slider142.I have edited my post.