Properties of natural log and absolute value

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SUMMARY

The discussion focuses on the transformation of the expression from -ln|x| to ln|x^-1| using properties of logarithms. The user correctly identifies that -ln|x| can be rewritten as -1 * ln|x|, which simplifies to ln(|x|^-1). This is further confirmed as equivalent to ln(1/|x|). The steps taken in the solution are validated, emphasizing the application of logarithmic properties.

PREREQUISITES
  • Understanding of logarithmic properties, specifically natural logarithms.
  • Familiarity with absolute value notation and its implications in logarithmic expressions.
  • Basic algebra skills, particularly with exponents and fractions.
  • Knowledge of mathematical notation and conventions used in calculus.
NEXT STEPS
  • Study the properties of logarithms, including the product, quotient, and power rules.
  • Explore examples of manipulating logarithmic expressions involving absolute values.
  • Learn about the implications of logarithmic transformations in calculus, particularly in integration.
  • Practice solving problems that involve converting between logarithmic forms and exponential forms.
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Students studying calculus, mathematics educators, and anyone interested in mastering logarithmic transformations and properties.

mech-eng
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Homework Statement


from -lnIxI to lnI x^-1I , I try to go from -lnIxI to lnI x^-1I by using some properties.


Homework Equations


- lnIxI


The Attempt at a Solution


First I write the -lnIxI as -1*lnIxI and then I use -1 as an exponent to absolute value of x in the natural log that is
ln ( IxI^-1) and then I take -1 inside the paranthesis and I arrive to ln Ix^-1I which is also ln I 1/x I.

Are my steps correct? If not, which step is incorrect?

Thank you.
 
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mech-eng said:

Homework Statement


from -lnIxI to lnI x^-1I , I try to go from -lnIxI to lnI x^-1I by using some properties.

Homework Equations


- lnIxI

The Attempt at a Solution


First I write the -lnIxI as -1*lnIxI and then I use -1 as an exponent to absolute value of x in the natural log that is
ln ( IxI^-1) and then I take -1 inside the paranthesis and I arrive to ln Ix^-1I which is also ln I 1/x I.

Are my steps correct? If not, which step is incorrect?

Thank you.
Looks OK to me, but it's more wordy than it needs to be.
##-ln |x| = -1 * ln|x| = ln(|x|^{-1}) ##
The last expression is the same as ##ln(\frac{1}{|x|})##
 

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