Understanding Ln Graph: Form & Deduction of P and L in V = Pe-LQ

  • Thread starter georgiemuc
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In summary, if V = Pe-LQ where P and L are constants, taking the logs of both sides can help you determine the form of the graph of lnV against Q. By applying the rules for dealing with logs, you can simplify the equation and potentially transform it into the equation of a straight line, y = mx + c. This can help you deduce the values of P and L. If you are stuck, it is helpful to post your progress so others can assist you.
  • #1
georgiemuc
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If V = Pe-LQ
Where P and L are constants,

Describe the form that a graph of lnV against Q should take and explain how P and L can be deduced?

Very very stuck, please help!
 
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  • #2
If you take logs of both sides

Ln(V) = Ln(Pe^-LQ)

you should then be able to apply the rules for dealing with logs to the equation and go from there.
 
  • #3
MalachiK said:
If you take logs of both sides

Ln(V) = Ln(Pe^-LQ)

you should then be able to apply the rules for dealing with logs to the equation and go from there.

I have tried this and just got myself in a massive mess haha, any help?
 
  • #4
You should post what you have done so that we can see where the problem is. the left hand side is just Ln(V), nothing has to happen to that. On the right you have two terms multiplied by each other.

You know that in general ln(AB) = ln(A) + ln(B), apply this and you should get something that looks like the equation of a straight line... remember y = mx + c?
 
  • #5


I am happy to assist you in understanding the form and deduction of P and L in the equation V = Pe-LQ. First, it is important to understand that lnV represents the natural logarithm of V, which is a mathematical function used to describe the relationship between two variables. In this case, V is dependent on Q, and lnV is plotted against Q on a graph.

The form of the graph of lnV against Q should be a straight line with a negative slope. This is because lnV is inversely proportional to Q, meaning as Q increases, lnV decreases. This relationship is represented by the negative sign in front of L in the equation. The value of P in the equation represents the y-intercept of the graph, which is the value of lnV when Q is equal to zero.

To deduce the values of P and L from the graph, we can use the slope-intercept form of a line, y = mx + b, where m is the slope and b is the y-intercept. In our case, the equation would be lnV = -LQ + P. By comparing this equation to the slope-intercept form, we can see that the slope is -L and the y-intercept is P. Therefore, the values of P and L can be deduced from the slope and y-intercept of the graph of lnV against Q.

In conclusion, the form of the graph of lnV against Q is a straight line with a negative slope, and the values of P and L can be deduced from the slope and y-intercept of the graph. I hope this explanation helps in your understanding of the ln graph and the deduction of P and L in the given equation.
 

Related to Understanding Ln Graph: Form & Deduction of P and L in V = Pe-LQ

1. What is an Ln graph?

An Ln graph is a logarithmic graph that uses the natural logarithm (Ln) function as its base. This type of graph is commonly used to plot data that grows or decays exponentially.

2. How do I plot data on an Ln graph?

To plot data on an Ln graph, you will need to calculate the natural logarithm of each data point and then plot the corresponding values on the graph. You can do this manually or by using a calculator or computer program.

3. Can an Ln graph be used for negative values?

Yes, an Ln graph can be used for negative values. However, the natural logarithm of a negative number is a complex number, so the graph will not be a simple curve. It is recommended to only use Ln graphs for positive values.

4. How is an Ln graph different from a regular logarithmic graph?

The main difference between an Ln graph and a regular logarithmic graph is the base of the logarithm. Ln graphs use the natural logarithm (base e) while regular logarithmic graphs can use different bases, such as base 10 or base 2. Additionally, the scales on the axes of an Ln graph are not evenly spaced like they are on a regular logarithmic graph.

5. What are some real-life applications of Ln graphs?

Ln graphs are commonly used in scientific and mathematical fields to plot data that follows an exponential growth or decay pattern. They are also used in economics and finance to model population growth, interest rates, and stock market trends. In the medical field, Ln graphs are used to track the concentration of drugs in the body over time.

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