Author Question: What is the second derivative of a logistic differential equation? (Read 1056 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?

Cucumber slices relieve headaches by tightening blood vessels, reducing blood flow to the area, and relieving pressure.

Did you know?

Bacteria have flourished on the earth for over three billion years. They were the first life forms on the planet.

Did you know?

Pope Sylvester II tried to introduce Arabic numbers into Europe between the years 999 and 1003, but their use did not catch on for a few more centuries, and Roman numerals continued to be the primary number system.

Did you know?

Hip fractures are the most serious consequences of osteoporosis. The incidence of hip fractures increases with each decade among patients in their 60s to patients in their 90s for both women and men of all populations. Men and women older than 80 years of age show the highest incidence of hip fractures.

Did you know?

There are approximately 3 million unintended pregnancies in the United States each year.

For a complete list of videos, visit our video library