1. 令x趋于正无穷大,F(+无穷大) =1, 得: A+0*B=1, 即A=1. F(x) 右边续, F(+0) = F(0)=0, 即:令x从大于0, 趋向于0,得A+B*1 =0, 即A+B=0, 得:B=-1.2. P(-1 =1-e^(-λ).
