设，n=1,2,...，则当时，依概率收敛到1。https://img-ph-mirror.nosdn.127.net/hZM0olij5nqNZIKK23DMOQ==/6630887445792453443.pnghttps://img-ph-mirror.nosdn.127.net/mEL1KYPaCfhCxvAqAqJDvw==/1438337131091693287.pnghttps://img-ph-mirror.nosdn.127.net/teFw9dWCjy4xgYnz-6BRCA==/6619337076142062534.png