Consider the differential equation $${{dy} \over {dx}} = 1 + {y^2}.$$ Which one of the following can be particular solution of this differential equation ?

It is known that two roots of the non-linear equation $$\,{x^3} - 6{x^2} + 11x - 6 = 0\,\,$$ are $$1$$ and $$3.$$ The third root will be