求大神解决一题高二数学题,图片中第一题选择题,要详细的解题过程

2025-04-30 02:22:43
推荐回答(2个)
回答1:

答:C
A(n+1)=2/An +1
A(n+2)=2/A(n+1) +1
A(n+2)=2/ [2/An +1] +1
A(n+2)=2An /(2+An) +1=1+2(2+An -2) /(2+An)
A(n+2)=3- 4/(2+An)
A1=1,A3=3-4/3=5/3
A5=3-4/(2+5/3)=3-12/11=21/11
选择C

回答2: