A:+3
B:+1
C:+5
D:+7
已知随机变量ζ服从正态分布N2,σ2,且Pξ<4=0.8,则P0<ξ<2=( )
He wants to answer the because it is an interesting one.
汽车以10m/s的速度在公路上匀速行驶,刹车后以2m/s2的加速度匀减速直线运动,求刹车后4s末的速度和8s内汽车通过的位移.