# 2nd derivative

1. Jan 22, 2009

### magma_saber

1. The problem statement, all variables and given/known data
What is the 2nd derivative of 3x - x(ln3)?

2. Relevant equations

3. The attempt at a solution
I got this:
f'(x) = 3x*ln3 -(ln3+x/3)
f''(x) = 3x*ln3*ln3 -1/3 - 1/3

2. Jan 22, 2009

### phreak

How did you get the x/3 part? And in your second derivative, are you claiming that $$\frac{d}{dx} ln(3) = \frac{1}{3}$$? You need to remember that ln(3) is a constant.