Can someone explain phase portraits(what they are, why we do them, etc) and direction fields on nullclines? Or give me a good reference for them?

Question

Can someone explain phase portraits(what they are, why we do them, etc) and direction fields on nullclines?  Or give me a good reference for them?

dan815 · Answer

what are nullclines?

fibonaccichick666 · Answer

I have no idea. (well, I have some, I think(not sure if it's right) they may be like 45 degrays on a coordinate plane) I don't really understand this. I mean I can google, I get http://en.wikipedia.org/wiki/Nullcline but I don't understand it and how to draw it

dan815 · Answer

ahh okay

dan815 · Answer

0 growth isoclines

dan815 · Answer

basically u find the 0 growth isoclines first and see how the differential equation is behaving around it and plot it

fibonaccichick666 · Answer

I don't know what an isocline is

dan815 · Answer

an isocline is one curve that shares the same inclination 
or in other worse a curve where all the slopes are the same, or all the rate of changes along the curve at the same

dan815 · Answer

Suppose you have a slope field, |dw:1428854684238:dw|