Author Question: What is the second derivative of a logistic differential equation? (Read 1057 times)

Sandstorm

  • Sr. Member
  • ****
  • Posts: 268
I can manage integrating it, but how to I take the second derivative?

I have a partial formula written down, but it's incorrect.

Thanks!



coco

  • Hero Member
  • *****
  • Posts: 739
This is the original equation below:
X(t) = (1 + ( (1/x) -1)e^(-rt) ) ^-1

Solve the denominator :
X(t) = (1 + ( (1 - x)/x)e^(-rt) ) ^-1

Solve for the lowest denominator and bring to the numerator
X(t) = X(X + e^(-rt) - Xe^(-rt) ) ^-1

Now take the first derivative:
X'(t) = -X(-re^(-rt) + Xre^(-rt) ) ^-2

Then take the second derivative
X''(t) = 2X(r^2e^(-rt) - Xr^2e^(-rt) ) ^-3

Make the equation into a nice form:
X''(t) = 2X/(r^2e^(-rt) - Xr^2e^(-rt) )^3

You may go ahead to seperate common variables but the most important point is about the mastery of the concept.

I hope this helps.



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
 

Did you know?

For high blood pressure (hypertension), a new class of drug, called a vasopeptidase blocker (inhibitor), has been developed. It decreases blood pressure by simultaneously dilating the peripheral arteries and increasing the body's loss of salt.

Did you know?

Although the Roman numeral for the number 4 has always been taught to have been "IV," according to historians, the ancient Romans probably used "IIII" most of the time. This is partially backed up by the fact that early grandfather clocks displayed IIII for the number 4 instead of IV. Early clockmakers apparently thought that the IIII balanced out the VIII (used for the number 8) on the clock face and that it just looked better.

Did you know?

On average, someone in the United States has a stroke about every 40 seconds. This is about 795,000 people per year.

Did you know?

The familiar sounds of your heart are made by the heart's valves as they open and close.

Did you know?

There are major differences in the metabolism of morphine and the illegal drug heroin. Morphine mostly produces its CNS effects through m-receptors, and at k- and d-receptors. Heroin has a slight affinity for opiate receptors. Most of its actions are due to metabolism to active metabolites (6-acetylmorphine, morphine, and morphine-6-glucuronide).

For a complete list of videos, visit our video library