Let XXX be continuous with PDF f(x)=2xe−x2f(x) = 2xe^{-x^2}f(x)=2xe−x2 for x≥0x \ge 0x≥0. What is P(X≤1)P(X \le 1)P(X≤1)?
1−e−11-e^{-1}1−e−1
e−1e^{-1}e−1
1−e−21 - e^{-2}1−e−2
e−2e^{-2}e−2