Here's the problem:
At any point of intersection of a solution curve of the d.e. y'=x+y and the line x+y=0, the function y at that point
(a) is equal to 0
(b) is a local maximum
(c) has a local minimum
(d) has a point of inflection
(e) has a discontinuity
First, what does "d.e." mean? Derivative?
Second, I have no clue how to figure this out, so any help would be much appreciated!