Plotting Direction Fields for Differential Equations: A Mathematica Tutorial

[DivGradCurl]

Does anybody know how to plot the direction field of y^{\prime} = 5 - 3\sqrt{y}?

I get error messages because the independent variable isn't there. I've attached a mathematica notebook that shows it.

Any help is highly appreciated.

 

[Townsend]

Does anybody know how to plot the direction field of y^{\prime} = 5 - 3\sqrt{y}?

I get error messages because the independent variable isn't there. I've attached a mathematica notebook that shows it.

Any help is highly appreciated.

Your Y values cannot be less than 0 since it has a y^.5, that's what is messing you up...stick to {y, 0, 10} and you will be fine...

 

[DivGradCurl]

You're definitely right. It has nothing to do with the independent variable, and I should have paid attention to the values of y. It works now! Thank you very much.

 

[James R]

What's a direction field?

 

[DivGradCurl]

James, take a look at this:

http://mathworld.wolfram.com/SlopeField.html

 

[James R]

Thanks, thiago_j.