题库网
#c28418e0-91f3-4201-a8cd-a969bf7fc82f简单填空题数列求和方法数列

10.已知正项数列{an}\{a_{n}\}中,a1=1,an+12an2=1{a_1}=1,a_{n+1}^2-a_n^2=1,则数列{1an+an+1}\left\{{\frac{1}{{a_n}+{a_{n+1}}}}\right\}的前120项和为((  ))