Register to reply 
Logarithmic functions 
Share this thread: 
#1
Jan2605, 04:23 PM

P: 17

y = logx 4
identify the domain and range state whether the function is increasing or decreasing, and identify the vertical asympotote, teh xintercept and the value of x at y = 1 I need some help! thank you in advance! 


#2
Jan2605, 04:27 PM

Sci Advisor
P: 6,058

The 4 in your expression appears to be hanging out in space. It would be helpful if you could write the equation more clearly.



#3
Jan2605, 04:28 PM

Sci Advisor
HW Helper
P: 11,915

So your function is:
[tex] y(x)=\log_{x} 4 [/tex] Can you determine the domain and range...?? Discuss the sign of its derivative... Daniel. P.S.Can u solve the equation y(x*)=1??Find x*... 


#4
Jan2605, 06:15 PM

Math
Emeritus
Sci Advisor
Thanks
PF Gold
P: 39,497

Logarithmic functions
I believe that log_{a}(x) is only defined for a> 0. Does that help.



#5
Jan2605, 06:58 PM

Sci Advisor
HW Helper
P: 1,123

Also I don't think that log_{a}(x) is defined for a=1.



#6
Jan2705, 03:54 AM

Sci Advisor
HW Helper
P: 11,915

Write
[tex] y(x)=\frac{\ln 4}{\ln x} [/tex] Cau u see now what is the range??What about the domain? Daniel. 


#7
Jan2705, 07:14 AM

P: 17

See I thought x was 2??



#8
Jan2705, 07:21 AM

Sci Advisor
HW Helper
P: 11,915

What "2"??Where did u pick it out???You mean the solution to the equation
[tex] \frac{\ln 4}{\ln x} =1 [/tex] I hope you're only kidding... Daniel. 


#9
Jan2705, 11:20 AM

P: 17

no, i'm kidding. this problem might as well be in chinese for all i understand of it



#10
Jan2705, 11:21 AM

P: 17

*** NOT kidding



#11
Jan2705, 11:27 AM

Sci Advisor
HW Helper
P: 11,915

Write it like that
[tex]\ln 4=\ln x [/tex] Use the fact that logaritm is a surjective function... Daniel. 


#12
Jan2705, 11:28 AM

P: 17

i'm sorry i'm not trying to be difficult i just completely dont understand what you are talking about.



#13
Jan2705, 11:36 AM

Sci Advisor
HW Helper
P: 11,915

Daniel. 


Register to reply 
Related Discussions  
Logarithmic Functions  Precalculus Mathematics Homework  14  
Logarithmic Functions  Calculus & Beyond Homework  3  
Exponential and Logarithmic functions  Calculus  5  
Intersect From Two Logarithmic Functions  General Math  3  
Logarithmic Functions  General Math  2 