# see also the ti89 directory form a calculus 3 class. Perhaps
http://www.math.fsu.edu/~bellenot/class/s05/cal3/ti89

1. Solve y' = y(2-y) y(0) = 3 graphically
	a. switch to DE mode:
		(MODE)
		graph->DIFF EQUATIONS
		ENTER
	b. enter the equation
		green diamond
		y= (F1)
		ENTER
		fill in equation
		y1'=y1*(2-y1)
		ENTER
		fill in intital value
		yi1=3
		ENTER
		green diamond
		window (F2)
		make sure  that 3 is between ymax and ymin and t0=0
		green diamond
		| (next to 7)
		There are several things that can screw up a DE plot the most important:
		fields->slpfld 
	c. field the graph
		green diamon
		graph (F3)
		you should now see a `Slope Field' and curve with a circle at the
		point t=0, y=3.

Variation 1. Give a set of intial values:
	a. We look at the curves where y(0) is 0, 1, 2, 3
		green diamond
		y= (F1)
		fill in
		yi1 = {0, 1, 2, 3}
		(the comma's don't show in one display, but are needed)
		(check that ymin < 0 and ymax > 3
		green diamond
		graph (F3)
		You should now see 4 curves with circles at time t=0.

2. Solve y' = y(2-y) y(0) analytically
	a. on the home screen
		F3 C (deSolve)
		fill in
		deSolve(y'=y*(2-y) and y(0)=3, t, y)
		the answer appears as
		1/y = 1/2-exp(-2t)/6