Calculating the 2nd Derivative of 3x - xln3 | Homework Help

[magma_saber]

Homework Statement

What is the 2nd derivative of 3^x - x(ln3)?

Homework Equations

The Attempt at a Solution

I got this:
f'(x) = 3^x*ln3 -(ln3+x/3)
f''(x) = 3^x*ln3*ln3 -1/3 - 1/3

 

[phreak]

f'(x) = 3^x \cdot ln3 -(ln3+\frac{x}{3})

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.