If X,YX, YX,Y are independent N(0,1)N(0, 1)N(0,1), what is the distribution of X2+Y2X^2+Y^2X2+Y2?
Chi−square(2)Chi-square(2)Chi−square(2)
Exponential(1/2)Exponential(1/2)Exponential(1/2)
Gamma(1,2)Gamma(1, 2)Gamma(1,2)
All of the above