Let XXX and YYY be independent with X∼U(0,1)X \sim U(0, 1)X∼U(0,1) and Y∼U(0,1)Y \sim U(0, 1)Y∼U(0,1). What is P(X2+Y2≤1)P(X^2 + Y^2 \le 1)P(X2+Y2≤1)?
12\frac{1}{2}21
14\frac{1}{4}41
π4\frac{\pi}{4}4π
π2\frac{\pi}{2}2π