What is the inverse of ln(x^2) and its symmetry properties?

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Homework Help Overview

The discussion revolves around finding the inverse of logarithmic functions, specifically ln(x^2) and ln(x^2 - 20), and exploring their symmetry properties. Participants are examining the nature of these functions and their inverses within the context of mathematical reasoning.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants are attempting to identify axes of symmetry for various functions, questioning the symmetry around the y-axis for ln(x^2 - 20) and discussing the implications of using "ln" as a variable. There are also inquiries about the correct formulation of inverses for the logarithmic functions.

Discussion Status

Some participants have provided guidance on the relationship between logarithmic and exponential functions, suggesting that the inverse of ln(x) is exp(x). There is an ongoing exploration of the inverses and their properties, with some participants expressing understanding and appreciation for the insights shared.

Contextual Notes

Participants are navigating potential misunderstandings regarding the use of "ln" and its implications for the functions being discussed. There are also mentions of domain and range restrictions related to the original functions, which are acknowledged but not resolved.

ludi_srbin
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f(x)=e^cosx

equation for the axis of symmetry?
I got x=pi


f(x)=ln(x^2 - 20)

describe symmetry??

I got symmetric arround y axis.

inverse??

I got y=sqr of ((x/ln) +20)

f(x)=ln(x^2)

Inverse?

I got y= sqr of (x/ln)
 
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Since cos x is a repeating function, it has an infinite number of axes of symmetry. They occur at n pi. Something similar needs to be done for exp(cos x).

For the others, you seem to be using "ln" as a variable of some sort. Remember that ln x is a function, with inverse exp(x). You might want to look at those again.
 
So for others I just change ln to exp?
 
So I get f(x)^-1=e^(X^2-20)

and

f(x)^-1=e^x^2
 
Let me take one of them. You should be able to do the rest.

y = ln(x^2 - 20)

exp(y) = x^2 - 20

x^2 = exp(y) + 20

x = sqrt(exp(y) + 20)

So, f^-1(x) = sqrt(exp(x) + 20)

Note that there are restrictions on the domain and range - these would correspond to the restrictions on the range and domain of the original function.

Does that help?
 
It does.

Thank you so much. :smile:
 

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