Find out if a solution exists. If it does, determine if it is unique.
dy/dx=sqrt(x-y); y(2)=2
My solution:
f(x,y)=sqrt(x-y) so the only restriction is x must be greater than or equal to y.
Since x=y, a solution exists.
fy(x,y)=1/2sqrt(x-y) so the only restriction is x-y cannot equal 0.
Since x-y=0, the solution may not be unique.