Functionshard
0:00.0

A function f:RRf: \mathbb{R} \to \mathbb{R} satisfies f(x+y)=f(x)+f(y)+2xyf(x+y) = f(x) + f(y) + 2xy. If f(1)=2f(1) = 2, find f(n)f(n) for any positive integer nn.