when y = 0, y' = 1 ... sketch a bunch of slopes = 1 along the x-axisy'=1-y^2

when y = 1, y' = 0 ... sketch a bunch of slopes = 0 along the line y = 1

when y = -1, y' = 0 ... sketch a bunch of slopes = 0 along the line y = -1

when y = 2, y' = -3 ... sketch a bunch of slopes = -3 along the line y = 2

when y = -2, y' = -3 ... sketch a bunch of slopes = -3 along the line y = -2

get the idea?