x Turn on thread page Beta
 You are Here: Home >< Maths

# P3 - Rates of changes watch

1. I really dont know how you derive a differential equation from a paragraph of writing of rates of change. I just dont understand it.

I can solve the differential equation, but i dont know how to derive it from text. Please could someone tell me what I should look for and how to do it, please!!!
2. (Original post by BlueAngel)
I really dont know how you derive a differential equation from a paragraph of writing of rates of change. I just dont understand it.

I can solve the differential equation, but i dont know how to derive it from text. Please could someone tell me what I should look for and how to do it, please!!!
put all the y on one side and all the x on the other side integrate both side, find c!
3. (Original post by tammypotato)
put all the y on one side and all the x on the other side integrate both side, find c!
no, she doesn't know how to write a differential equation, when given a load of text
4. (Original post by BlueAngel)
I really dont know how you derive a differential equation from a paragraph of writing of rates of change. I just dont understand it.

I can solve the differential equation, but i dont know how to derive it from text. Please could someone tell me what I should look for and how to do it, please!!!
look for something like "the rate of change of ..... is proportional to ....."

e.g. Water leaks out of a tank. the rate of decrease in V (volume) is proportional to V. write a differential equation:

dV/dt proportional to V
dV/dt = -kt (- since it is decreasing)
5. (Original post by mockel)
look for something like "the rate of change of ..... is proportional to ....."

e.g. Water leaks out of a tank. the rate of decrease in V (volume) is proportional to V. write a differential equation:

dV/dt proportional to V
dV/dt = -kt (- since it is decreasing)

Thank you very much, you get rep.

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: June 9, 2004
Today on TSR

Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams