Can a Taylor series approximation be used to solve a mixed logarithmic equation?

In summary, the conversation discusses solving a "mixed" logarithmic equation, specifically e^(-66/x)/x^2 = c, where c is a constant. The suggested method is to take ln of both sides and divide by 2, but this may not provide a precise solution. The conversation also considers using a Taylor series approximation for the ln term, but notes that it may not be applicable for values of x greater than 1. Ultimately, it is determined that the equation cannot be solved in terms of elementary functions and an approximate solution will need to be found.
  • #1
Esd
15
0
"mixed" logarithmic equation

Homework Statement


I'm trying to solve for x in the following equation: e^(-66/x)/x^2 = c, where c is a constant

Homework Equations


The Attempt at a Solution


By taking ln of both sides and then dividing by 2, I get to:

-33/x -ln(x) = c/2

Then, in order to get an approximate answer, I tried substituting e with its approximation up to a few decimal places, in the original problem statement, but that didn't get me far. I'm considering doing a Taylor series approximation for the 'ln(x)' term (i.e (x-1) - (x-1)^2 + (x-1)^3)) and then solving for x. Is there an easier and/or more precise and/or more direct way? Note, I understand that the taylor approximation I used is meant for x, such that |x| is at most 1. This is why I only went with 3 terms.

Homework Statement


Homework Equations


The Attempt at a Solution

 
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  • #2


Have you considered arranging it in such a way where the X could be factored out?
 
  • #3


Considered? Yes. But can't think of how.
 
  • #4


The equation can't be solved in terms of elementary functions - in other words, you can't factor out an x - so you will need to find an approximate solution to the problem.
 

What is a mixed logarithmic equation?

A mixed logarithmic equation is one that contains both logarithmic and non-logarithmic terms. It can be solved by using logarithmic properties and algebraic techniques.

How do you solve a mixed logarithmic equation?

To solve a mixed logarithmic equation, you must first isolate the logarithmic term on one side of the equation. Next, use logarithmic properties to simplify the equation. Finally, use algebraic techniques to solve for the variable.

What are some common properties used to solve mixed logarithmic equations?

The most common properties used to solve mixed logarithmic equations are the product, quotient, and power rules of logarithms. These properties allow you to simplify the equation and isolate the logarithmic term.

Can a mixed logarithmic equation have more than one solution?

Yes, a mixed logarithmic equation can have more than one solution. This is because logarithmic functions are not one-to-one, meaning multiple inputs can result in the same output. Therefore, it is important to check your solution(s) by plugging them back into the original equation.

Are there any restrictions when solving a mixed logarithmic equation?

Yes, there are some restrictions when solving a mixed logarithmic equation. The argument of a logarithm must always be positive, so any values that make the argument negative or zero are considered extraneous solutions and must be rejected.

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