1.
Let NN be the set of natural numbers and a relation RR on NN be defined by R={(x,y)∈N×N:x3−3x2y−xy2+3y3=0}R = \{(x, y) \in N \times N : x^3 - 3x^2 y - xy^2 + 3y^3 = 0\}. Then the relation RR is