# Another differentiation question

1. Mar 3, 2008

### chaosblack

1. The problem statement, all variables and given/known data

Supposed "f" is a differentiable function. Write the expression for the derivative of the following function.

a) h(x) = -4x^3 * f(x)

b) h(x) = 2/$$\sqrt{x}$$* f(x)

2. Relevant equations

N/a

3. The attempt at a solution

Would the answers just be (using the product rule)

a) h'(x) = -4x^3 * f '(x) + f(x) * -12x^2

and

b) h'(x) = 2/$$\sqrt{x}$$ * f '(x) + f(x) * -x^-2

Sort of seems to simple... Thanks again

2. Mar 3, 2008

### jhicks

a) Yes, b) $$\frac{2}{\sqrt{x}}$$ is not $$\frac{-1}{x^2}$$

Last edited: Mar 3, 2008