(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

http://www.wolframalpha.com/input/?i=((1+/+x)+++2)+/+(3(2x+++lnx))^(2/3)+=+0

Solve the equation f'(x) = 0

f(x) = (ln x + 2x)^(1/3)

3. The attempt at a solution

As you can see, for the function

((1 / x) + 2) / (3(2x + lnx))^(2/3) = 0

I can get a value for x which is - 1 / 2

But my text book says "no solution"

Why is that?

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Why is this?

**Physics Forums | Science Articles, Homework Help, Discussion**