Sketching Direction field on ti-nspire cas

[ckboz]

hi, does anyone know how to sketch differential equation on cas. i know how to do it for equations that has x in equation, but i dont know how to sketch ones on cas that has y in the equation.(e.g dy/dx=y^2/x^2)
thanks for reading

[keltingmeith]

Firstly: I would not suggest doing this in a SAC or an exam. This can turn into a rather arduous process and can be a time killer, and I found last year in timed practices that it was not worth it. Unless you have to sketch the direction field yourself, and the direction field is incredibly complicated, you're better off just logicing it. Now, to answer your question:

To do this on the TI-nspire (you do need to specify these things, I don't know how to do it for the classpad), you just need to type in the equation as you'd expect it. (In your example, y^2/x^2). However, check what y' you're dealing with - it will say this just left to the box where you're entering the equation. If should say, for example, y1 '. In this case, you'd put y1^2/x^2. If it was y2 ', you'd put y2^2/x^2, and so on and so forth.