已知数列{an}满足a1=4,an=4-(4/a的n-1项)(n大于等于2)令bn=1/an-2 (1)求证数列{bn}

已知数列{an}满足a1=4,an=4-(4/a的n-1项)(n大于等于2)令bn=1/an-2 (1)求证数列{bn}是等差数列 ...已知数列{an}满足a1=4,an=4-(4/a的n-1项)(n大于等于2)令bn=1/an-2 (1)求证数列{bn}是等差数列 (2)求数列{an}的通项公式