Solve x in [0,2π]: Logs Homework Help

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To solve the equation 2cos(x/3) = LnX in the interval [0, 2π], the initial steps lead to x = e^1, resulting in x ≈ 2.718, which is confirmed as correct. A subsequent calculation shows that if x = e^(Ln3) + Ln(e^2) - 5Ln(1), then x simplifies to 5, which is also verified as correct. The discussion then shifts to finding the relative maximum of the function y = (LnX)/X and determining the domain of Ln(X^2-1). To find the relative maximum, the derivative should be set to zero, and the value of the function at that point can be evaluated. Overall, the thread covers solving logarithmic equations and analyzing functions for maxima and domain constraints.
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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?
 
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Was that supposed to be \cos \frac {\pi}{3}?
 
yes sorry, that is 2cos(pi/3)=LnX
 
Last edited:
In that case, good job!
 
how do I find the relative maximum value of the function y=(LnX)/X and the domain of the function Ln(X^2-1)?
 
Just find the derivative of the function and set it to zero.
 
for the domain or for the max value?
 
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.
 
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