设随机变量(X,Y)的分布函数F(x,y)=1/π2[π/2+arctan(x/3)][π/2+arctan(y/2)],则(X

设随机变量(X,Y)的分布函数F(x,y)=1/π2[π/2+arctan(x/3)][π/2+arctan(y/2)],则(X,Y)的概率密度为____.


【正确答案】:

f(x,y)=6/[π2(9+x2)(4+y2)]