Question

I am so confused on what to do with fractions.

Answer 1

Using the power rule for differentiation, the first derivative of

`f(x) = -x^(\frac12)`

is

`f'(x) = -\frac12 \cdot x^(\frac12-1) = -\frac12 x^(-\frac12)`

and the second derivative is

`f''(x) = -\frac12 \cdot \left(-\frac12 \cdot x^(-\frac12 - 1)\right) = \frac14 x^(-\frac32)`

which makes E the correct choice.