Use the properties of logaritms to expand the expression

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SUMMARY

The discussion focuses on expanding the logarithmic expression ln((4x^5 - x - 1)(√(x - 7)) / (x^2 + 1)^3) using properties of logarithms. Key points include the correct usage of the natural logarithm function, denoted as ln, and the application of logarithmic properties such as ln(AB) = ln A + ln B and ln(a^b) = b ln a. The user initially misuses the notation and multiplication, leading to confusion in their calculations. Correcting these errors is essential for accurately expanding the expression.

PREREQUISITES
  • Understanding of natural logarithms (ln) and their properties
  • Familiarity with algebraic expressions and manipulation
  • Knowledge of square roots and exponents
  • Basic skills in simplifying mathematical expressions
NEXT STEPS
  • Study the properties of logarithms in detail, focusing on ln(AB) and ln(a^b)
  • Practice simplifying complex logarithmic expressions
  • Learn about common mistakes in logarithmic calculations
  • Explore additional examples of logarithmic expansions in calculus
USEFUL FOR

Students studying algebra, particularly those working on logarithmic functions and expressions, as well as educators looking for examples of common errors in logarithmic manipulation.

pooker
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Homework Statement



IN * ((4x^5 - x -1)(square root x-7)) / (x^2 + 1)^3





The Attempt at a Solution



in(4x^5 - x - 1) + in(square root x-7) - in(x^2 + 1)^3

in(4x^5 - x - 1) + 1/2in(x-7) - 3in(x^2 +1)

5in4x - inx - 1 + 1/2(inx -in7) - 3 (2inx + in)


I know that's not right but its all I can think of at the moment.
 
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pooker said:

Homework Statement



IN * ((4x^5 - x -1)(square root x-7)) / (x^2 + 1)^3





The Attempt at a Solution



in(4x^5 - x - 1) + in(square root x-7) - in(x^2 + 1)^3

in(4x^5 - x - 1) + 1/2in(x-7) - 3in(x^2 +1)

5in4x - inx - 1 + 1/2(inx -in7) - 3 (2inx + in)


I know that's not right but its all I can think of at the moment.

First off, it's not in, it's ln (ell en), short for logarithm naturalis or something close to that. Before being able to help you out, can you confirm that this is the problem?
[tex]ln \frac{(4x^5 - x - 1)(\sqrt{x - 7})}{(x^2 + 1)^3}[/tex]

If so, then an expression of the form ln[(AB)/C] can be rewritten as ln A + ln B - ln C.
Then because the individual expressions B and C have exponents, you can use the property of logarithms that ln a^b = b ln a.

Mistakes in your work:
1. You start with IN *. I've already mentioned that it is LN, but the mistake here is the mulitiplication symbol. ln is a function, not a number, so it's meaningless to think of using it to multiply.
2. In your later work you have "3in(x^2 +1)" and in the next line you have "3 (2inx + in)". This suggests to me that you think that "in" is a number. It's not. 2 inx + in is meaningless.
 

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