Solving logarithm problem for Y

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Homework Help Overview

The discussion revolves around solving the equation 3e3y-6 = 2x2-1 for y, particularly focusing on the conditions under which solutions for x exist.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants explore the implications of the domain of logarithmic functions, questioning what is meant by "values of x for which a solution exists." They discuss the nature of the equation and the conditions under which the left-hand side can yield valid results.

Discussion Status

Multiple interpretations of the problem are being explored, particularly regarding the constraints on x due to the properties of logarithms and exponential functions. Some participants have provided insights into the positivity requirement of the left-hand side of the equation.

Contextual Notes

There is an emphasis on the domain restrictions of logarithmic functions, noting that solutions are not valid for x values less than or equal to zero.

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(For those values of x for which a solution exists), solve the following equation for y

3e3y-6 = 2x2-1

What does it mean by the values of x exists??
 
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fr33pl4gu3 said:
(For those values of x for which a solution exists), solve the following equation for y

3e3y-6 = 2x2-1

What does it mean by the values of x exists??
Because of the nature of the domain of the logarithm one can not evaluate y=\ln x for all x. Specifically the domain of the logarithm is all positive numbers. Therefore, we say that no solution exists for y=\ln x in the domain x\in\left(-\infty, 0\right].

So the question is asking you to solve the equation for y, for all values of x which exist. I hope that makes sense.
 
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fr33pl4gu3 said:
(For those values of x for which a solution exists), solve the following equation for y

3e3y-6 = 2x2-1

What does it mean by the values of x exists??

Say you have ln(x)=y.
This could be seen as e^y=x
It is impossible to raise any real number to any power and have it equal 0 or any number below that (feel free to try, in fact, I encourage it). Since it can't exist as x\in(-\infty,0), there are only certain numbers it can exist as.
 
fr33pl4gu3 said:
(For those values of x for which a solution exists), solve the following equation for y

3e3y-6 = 2x2-1

What does it mean by the values of x exists??

Hi fr33pl4gu3! :smile:

Simple answer:

3e3y-6 can only be positive.

So the equation doesn't work if 2x2-1 is negative or zero. :smile:
 

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