@Voyager,
Furthermore,in physical sense,I clear you that when x=0, y becomes maximum and have to give certain value.But when we put x=0 in this solution , y=0+0/0 and this become unexpected.so can you have any other possible solution.
If you convert this into second order,then it becomes:
d/dx(dy/dx)-2bydy/dx+a=0
and if we slove the differential equation in homogeneous form then two possible solution be y=-b/x and y=-tan bx.Then if we try to find the general solution for non homogeneous form,then integration appears become unsolved.Can you you slove this type of integral terms?,if you have time please try to observe the solution of this differential equation in this way.If you provide me,any idea for this integration,then result obtained may be interpreted in physiological sense also.So I hopely requested you for this.