Can the Nth Derivative Formula for ln(x) Be Extended to ln(x+c)?

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Discussion Overview

The discussion centers around the possibility of extending the nth derivative formula for ln(x) to ln(x+c), where c is a constant. Participants explore methods and implications of this extension, including the use of the chain rule and implicit differentiation, as well as the challenges posed by more complex functions.

Discussion Character

  • Exploratory
  • Technical explanation
  • Mathematical reasoning

Main Points Raised

  • One participant inquires about a formula or method to derive the nth derivative of ln(x+c), expressing curiosity about extending the known formula for ln(x).
  • Another participant suggests using the chain rule or the definition of the derivative to relate the nth derivative of ln(x+c) to that of ln(u) where u = x + c.
  • A different approach is proposed involving implicit differentiation of y = ln(g(x)), leading to a formula for the derivative in terms of g(x) and its derivative g'(x).
  • One participant provides specific derivatives for ln(x+c), stating that the nth derivative can be expressed as (n-1)!(-1)^(n+1)/(x+c)^n for n=1,2,3,4,...
  • There is a mention of the derivative of ln(x) being 1/x, which is noted as a fundamental result in calculus.

Areas of Agreement / Disagreement

Participants present various methods and formulas, but there is no consensus on a single approach or formula for the nth derivative of ln(x+c). The discussion remains open with multiple viewpoints and techniques being explored.

Contextual Notes

Some limitations include the potential complexity of deriving nth derivatives for more complicated functions, which may lead to complicated sums that are not addressed in the discussion.

islandboy401
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Is there a formula or a method to derive the nth derivative of ln (x+c)...(where c is any number...such as 1, 2, 3, etc)?

I know that there is a formula for the nth derivative of ln x, but I was wondering if this formula can be extended to one we can use when we are dealing with the nth derivative of something slightly more complicated.
 
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Use the chain rule or the definition of the derivative to show that f(n)(x + c) is the same as f(n)(u) if you let u = x + c.
 
Last edited:
You should try to derive a formula for the derivative of y = ln(g(x)). The way I would do that is using implicit differentiation, namely:

y = ln(g(x))

e^{y} = g(x)

\frac{dy}{dx} e^{y} = \frac{dg}{dx}

\frac{dy}{dx} = \frac{g'(x)}{g(x)}

Hope this helps.
 
yes
[log(x+C)]'=1/(x+C)
[log(x+C)]''=-1/(x+C)^2
(D^n)[log(x+C)]=(n-1)!(-1)^(n+1)/(x+C)^n
for n=1,2,3,4,...

is can be done for other simple functions like sin(x), exp(x), and x^a. The trouble with more complicated functions is complicated sums arise.

The derivative of the natural logarithm function, ln(x), with respect to x is given by:

$$\frac{d}{dx} \ln(x) = \frac{1}{x}$$

So, the derivative of ln(x) is 1/x. This is a fundamental result in calculus and is often used when finding derivatives of logarithmic functions.
 
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