Series expansion of logarithmic function

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SUMMARY

The discussion focuses on finding the first three non-zero terms in the series expansion of the logarithmic function ln(5+p) for small values of p. The correct approach involves rewriting the function as ln(5[1+(p/5)]) and applying the properties of logarithms. This leads to the series expansion of ln(1+(p/5)), which can be expressed as (p/5) - (1/2)(p/5)^2 + (1/3)(p/5)^3. The accuracy of the expansion is contingent upon the proximity of p to -4, but the task specifically requires only the first three non-zero terms.

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seboastien
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Homework Statement


Find first three non zero terms in series expansion where the argument of funstion is small

ln(5+p)

Homework Equations





The Attempt at a Solution



The only way I could think how to do this is by saying ln(5+p) = ln(1+(4+p)) and expanding to

(4+p)- 1/2(4+p)^2 + 1/3(4+p)^3 - ... however, I imagine that this would only work if p was approx -4.
 
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Come on guys! I really need to know how to do this!
 
seboastien said:

Homework Statement


Find first three non zero terms in series expansion where the argument of funstion is small

ln(5+p)

Homework Equations





The Attempt at a Solution



The only way I could think how to do this is by saying ln(5+p) = ln(1+(4+p)) and expanding to

(4+p)- 1/2(4+p)^2 + 1/3(4+p)^3 - ... however, I imagine that this would only work if p was approx -4.
Well, the accuracy, for any finite polynomial expansion, deteriorates as p gets farther from -4 but is the accuracy really relevant? You are only asked to "Find first three non zero terms".
 
How do I find the first three non-zero terms of ln(5+p), I'm pretty sure that my answer is wrong.
 
You'll want to write this as ln( 5 [ 1+(p/5) ] ) ; then use the properties of logarithms to write it as two terms, one of which is the term you would do the series expansion for.
 
Thank you
 

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