题目
设X sim N(0,1)，Phi(x) = (1)/(sqrt(2pi)) int_(-infty)^x e^-(t^2)/(2) dt，(x geq 0),则下列等式不成立的是( )A. Phi(x) = 1 - Phi(-x)B. Phi(0) = 0.5C. Phi(-x) = Phi(x)D. P(|X|
设$X \sim N(0,1)$，$\Phi(x) = \frac{1}{\sqrt{2\pi}} \int_{-\infty}^{x} e^{-\frac{t^2}{2}} dt$，$(x \geq 0)$,则下列等式不成立的是( )
A. $\Phi(x) = 1 - \Phi(-x)$
B. $\Phi(0) = 0.5$
C. $\Phi(-x) = \Phi(x)$
D. $P(|X| < a) = 2\Phi(a) - 1$
题目解答
答案
C. $\Phi(-x) = \Phi(x)$