SLOPE FIELDS

[jules]

I think this question was from Kilbaha 08
But in a slopefield question

dy/dx= -y/2
obviously through antidifferentiation
we get
x=-2log[y]+c

we are given the information x=0 and y= -1
If we are finding y in terms of x.
When you use the initial equation to find c, we end up with e^-x/2
However if we rearrange it first and then find c, we end up with -e^-x/2

cause therefore we end up with two equations?

[shinny]

That's why the anti-diff formula for the above case has a modulus sign around the log. However, you have to eliminate one of those two equations using the point given, so you'd take the negative equation.