Solving for x in logarithm problem

  • Thread starter Sumedh
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    Logarithm
In summary, the conversation is about solving an equation with four possible solutions. The equation has one irrational solution, no prime solution, two real solutions, and one integral solution. The person is seeking help on how to find the values of x for the equation. They have tried applying the base changing property and doing the L.C.M of both equations but are unable to solve further. Another person suggests using logarithm base 2 and provides steps to solve the equation. The conversation ends with the person thanking the other for their help and stating that they have found the answer.
  • #1
Sumedh
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Homework Statement


The equation (attached as image) has
(a)one irrational solution
(b)no prime solution
(c)two real solutions
(d)one integral solution

i would like to get help on how to find the possible values of x

Homework Equations


( the equation is attached below)


The Attempt at a Solution


i solved the equation by applying the base changing property and then doing
L.C.M of both equations but after that i am unable to solve further?

Any help will be highly appreciated.
 

Attachments

  • equation.png
    equation.png
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  • #2
Show what you tried so far.

What results did you have?

I suggest: Do change of base with base of 2 .
 
  • #3
The equation (attached as image) has
(a)one irrational solution
(b)no prime solution
(c)two real solutions
(d)one integral solution

i would like to get help on how to find the possible values of x

i solved the equation by applying the base changing property and then doing
L.C.M of both equations but after that i am unable to solve further?

Any help will be highly appreciated.
 

Attachments

  • equatin.png
    equatin.png
    984 bytes · Views: 505
  • #4
Because the numbers seem to be related to powers of 2, I was convinced to work with logarithm base 2. Let [itex]lb[/itex] stand for [itex]log_{2}[/itex].

We then have

[tex]log_{x^2}(16) + log_{2x}(64)[/tex]
[tex]= \frac{lb(16)}{2\cdot lb(x)} + \frac{lb(64)}{lb(2x)}[/tex]
[tex]= \frac{2}{lb(x)} + \frac{6}{lb(x) + 1} = 3[/tex]

this reduces to a quadratic which should be easily solvable.
 
  • #5
2/log2(x) + 6/ (log2(x)+1)=3
i got this result
after that what should i do
 
  • #6
logx^2 16 + log2x 64 = 3
log(16) /log (x2) + log(64) /log(2x) = 3
log(2x) log(16) + log(64) log (x2) = 3 log(2x) log (x2)
log(2x) log(24) + log(26) log (x2) = 3 log(2x) log (x2)
4 (log 2+log x) log(2) + 12 log(2) log (x) = 6 (log 2 + log x) log x
4 (log 2)2 + 4 log (x) log (2) + 12 log (2) log (x) = 6 log (2) log (x) + 6 (log x)2
4 (log 2)2 + 10 log (2) log (x) = 6 (log x)2

Solve the quadratic formula for log x and you'll get your answer.
 
Last edited:
  • #7
:smile:Thanks a lot i have got the answer:smile:
answer are x=4 and x=1[itex]/\sqrt[3]{}2[/itex]
 

FAQ: Solving for x in logarithm problem

What is a logarithm?

A logarithm is a mathematical function that helps us solve for the exponent in an exponential equation. It is the inverse operation of an exponential function.

Why do we need to solve for x in logarithm problems?

Solving for x in logarithm problems helps us find the unknown variable in an exponential equation. It is also useful in solving real-world problems involving exponential growth or decay.

How do I solve for x in logarithm problems?

To solve for x in logarithm problems, you can use the properties of logarithms, such as the power rule, product rule, and quotient rule. You can also use the change of base formula or graphing techniques to find the solution.

Can logarithms be negative or zero?

No, logarithms can only be positive. This is because the logarithmic function is only defined for positive numbers. If the base of the logarithm is a positive number, the result will always be positive.

What are some common mistakes to avoid when solving for x in logarithm problems?

Some common mistakes to avoid when solving for x in logarithm problems include forgetting to apply the properties of logarithms, making errors in simplifying expressions, using the wrong base in the calculation, and not checking the solution for extraneous values.

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