Let XXX and YYY be continuous with joint PDF f(x,y)=kf(x,y) = kf(x,y)=k for 0≤x≤1,0≤y≤10 \le x \le 1, 0 \le y \le 10≤x≤1,0≤y≤1. Find kkk.
0.5
1
2
4