# Applying ln to a graph: where would it be continuous?

1. Dec 18, 2011

### smeiste

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

2. Relevant equations

I'm looking over in old midterm to prepare for a final and can't figure out what the correct answer is. No answers were ever given. I'm not cheating on anything, would just like to know what the correct answer is and why :)

3. The attempt at a solution
I think the answer is either B or C but I can't decide.

2. Dec 18, 2011

### SammyS

Staff Emeritus
What is the domain of ln(u) ?

3. Dec 19, 2011

### smeiste

um positive numbers only.

4. Dec 19, 2011

### Dick

Ok, so where is g(x) positive?

5. Dec 20, 2011

### smeiste

from zero to infinity

6. Dec 20, 2011

### Dick

I meant for what values of 'x' is g(x) positive? That's what you need to know.

7. Dec 20, 2011

### SammyS

Staff Emeritus
The question is: "For what values of x is g(x) greater than zero?" Don't forget that in order for g(x) > 0, x must also be in the domain of g.

8. Dec 20, 2011

### smeiste

ohh okay. so the answer is B?

9. Dec 20, 2011

B is right.