Finding the Solution for x in a Natural Logarithm Equation

In summary, the conversation discusses solving for x in the equation xln(x)-24+6ln(x)-4x=0. The equation is simplified by moving terms to the other side and converting natural logarithms to exponent form. However, the solution may not be possible in terms of simple algebraic functions and may require the use of the W function. The conversation ends with a hint to continue factoring the equation.
  • #1
statusquorulz
1
0

Homework Statement



Solve for x

xln(x)-24+6ln(x)-4x=0


My attempt at the solution

I first moved "-24" and "-4x" to the right side of the equation yielding

xln(x)+6ln(x)=24+4x

I then converted the natural logarithms to exponent form and product form yielding

ln(x)^x+ln(x)^6 = 24+4x ====> ln(x^x*x^6)=24+4x =====> ln(x^(x+6))=24+4x

I then converted the equation in notation " e " form yielding

e^(24+4x)= x^(x+6)

Now I am stuck on where to proceed. I am aware that the answer has to be a positive number because the domain of a logarithm is always greater then 0.

Thanks
 
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  • #2
That is not going to have a solution in terms of any simple algebraic function. It might have a solution in terms of the "W" function which is defined as the inverse function to [itex]f(x)= xe^x[/itex].
 
  • #3
You were on the right track when you collected like terms:
xln(x)+6ln(x)=24+4x

If you factor the LHS further, notice:
ln(x) (x+6)=24+4x

Can you figure out what x must be now? (Sorry, Mr. Lambert. No soup for you today.)
 

FAQ: Finding the Solution for x in a Natural Logarithm Equation

1. What is a natural logarithm?

A natural logarithm is a mathematical function that represents the inverse of the exponential function. It is written as ln(x) and is used to solve for the power that the base e must be raised to in order to get the given value of x.

2. How do I solve a natural logarithm?

To solve a natural logarithm, you must use the properties of logarithms. First, rewrite the logarithm in exponential form. Then, simplify the expression by using properties such as the power rule, product rule, or quotient rule. Finally, solve for the variable by isolating it on one side of the equation.

3. What is the value of e in natural logarithms?

e, also known as Euler's number, is a mathematical constant that is approximately equal to 2.71828. It is the base of the natural logarithm and is used in many scientific and mathematical calculations.

4. Can natural logarithms have negative values?

No, natural logarithms can only have positive values. This is because the domain of the natural logarithmic function is restricted to positive real numbers. If a negative value is entered, the function is undefined.

5. How can I use natural logarithms in real life?

Natural logarithms have many practical applications in fields such as finance, physics, biology, and chemistry. They can be used to model population growth, calculate interest rates, predict radioactive decay, and determine pH levels in solutions.

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