# Thread: differential equation-drawing isocline and flow vector

1. ## differential equation-drawing isocline and flow vector

i have problem with drawing isoclines and flow vectors

2. Originally Posted by szpengchao

i have problem with drawing isoclines and flow vectors
Letting $\frac{dy}{dx}=c$

we see that $c=\frac{x-2y}{2x+y}\Rightarrow{y=\frac{5x}{c+2}-2x}$

Now letting c be equal to certain numbers sketch your isoclines

and considering c is a constant your isoclines are lines

3. ## yeah

yeah...i got that...but i saw others' work, there are not only straight lines but some vector...

how can u draw the flow vector diagram for this?