# Homework Help: Logs homework help

1. Sep 11, 2004

### UrbanXrisis

How do I solve for x in the interval [0,2pi]:
2cos(x/3)=LnX

Here's what I got:

2(.5)=LnX
1=LnX
e^(1)=x
x=2.718
is this correct?

If x=e^(Ln3)+Lne^2-5Ln1
what is x?
x=3+2-0=5
is this correct?

2. Sep 11, 2004

### Tide

Was that supposed to be $\cos \frac {\pi}{3}$?

3. Sep 11, 2004

### UrbanXrisis

yes sorry, that is 2cos(pi/3)=LnX

Last edited: Sep 11, 2004
4. Sep 11, 2004

### Tide

In that case, good job!

5. Sep 11, 2004

### UrbanXrisis

how do I find the relative maximum value of the function y=(LnX)/X and the domain of the function Ln(X^2-1)?

6. Sep 12, 2004

### Tide

Just find the derivative of the function and set it to zero.

7. Sep 12, 2004

### UrbanXrisis

for the domain or for the max value?

8. Sep 12, 2004

### Tide

That will give you the location of the relative maximum (you can verify that it is a maximum as opposed to a minimum). Then use that value of x that you find to determine the value of the function at that point.