(1)F(X,Y)=f(0,1)f(01)cx^2ydydx=c/2f(0,1)x^2dx=c/6x^3(0,1)=c/6=1c=6(2)P{X<0.5,Y<0.5}=f(0,0.5)F(0,0.5)6x^2ydydx=f(0,1)3/4x^2dx=1/32(3)fx(X)=f(0,1)6x^2ydy=3x^2(4)E(X)=f(0,1)xfx(X)dx=f(0,1)3x^3dx=3/4(5)cov(x,y)=E(XY)-E(X)E(Y)后面的敏如自己算含肆啊,有事要走开谈拿轿