问答题 假定随机过程X(t)和Y(t)是单独并联合平稳的。试求
【正确答案】RZ(t,t+τ)=E{[X(t)+Y(t)][X(t+τ)+Y(t+τ)]}=E[X(t)X(t+τ)]+E[Y(t)Y(t+τ)]+E[Y(t)X(t+τ)]+E[X(t)Y(t+τ)]=RX(τ)+RY(τ)+RXY(τ)+RYX(τ)
【答案解析】
【正确答案】在X(t)和Y(t)不相关时,
   RXY(τ)=RYX(τ)=0
   RZ(τ)=RX(τ)+RY(τ)
【答案解析】