2y''+(y')^3=0

y(0)=5

y'(0)=0

i need to deside on :

A.is it increasing or decreasing or a constant on the surroundings of 0

B.does it has a solution

C.does it have two solutions in which one of the increasing the other is decreasing

and i can solve it:

z=y'

i got 2/z=y+c

2/y'=y+c

but when i want to find C

i get

2/0=5+c

??

z=dy/dx=y'

dz/dy=zz'

2z'z+z^3=0