Equivalence of Logarithmic Expressions: Solving a Simple Algebra Question

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SUMMARY

The discussion centers on the equivalence of two logarithmic expressions: 9 * ln | sqrt(4+x^2)/2 + x/2 | and 9 * ln | sqrt(4+x^2) + x |. It is established that these expressions are not equivalent in value for all x, but they share the same derivative due to the properties of logarithmic differentiation. The key insight is that ln(f(x)/2) can be rewritten as ln(f(x)) - ln(2), where the derivative of ln(2) is zero, thus confirming their derivative equivalence.

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Homework Statement


how are these two problems equivalent?


Homework Equations


9 * ln | sqrt(4+x^2)/2 + x/2 | --->> = 9 * ln | sqrt(4+x^2) + x|


The Attempt at a Solution


i assume this has something to do with log rules.
 
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whatlifeforme said:

Homework Statement


how are these two problems equivalent?


Homework Equations


9 * ln | sqrt(4+x^2)/2 + x/2 | --->> = 9 * ln | sqrt(4+x^2) + x|


The Attempt at a Solution


i assume this has something to do with log rules.

Those aren't problems, they are expressions. And they aren't equivalent, they are different numbers when you put a value in for x. What is true is that they have the same derivative. ln(f(x)/2)=ln(f(x))-ln(2). If you differentiate the derivative of ln(2) is zero.
 

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