早教吧 育儿知识 作业答案 考试题库 百科 知识分享

a1=1,an+1=3an+n^2+n则an=?a1=1,an+1=3an+6^n,an=?a1=2,an*an+1=r^n,an=?a1=1,an+1=3an+n^2+n则an=?a1=1,an+1=3an+6^n,an=?a1=2,an*an+1=r^n,an=?(r是常数)

题目详情
a1=1,an+1=3an+n^2+n则an=?a1=1,an+1=3an+6^n,an=?a1=2,an*an+1=r^n,an=?
a1=1,an+1=3an+n^2+n则an=?
a1=1,an+1=3an+6^n,an=?
a1=2,an*an+1=r^n,an=?(r是常数)
▼优质解答
答案和解析
(1) a(n+1)=3an+n²+n设a(n+1)+k(n+1)²+p(n+1)+q=3(an+kn²+pn+q)即a(n+1)+kn²+(2k+p)n+(k+p+q)=3an+3kn²+3pn+3q∴a(n+1)=3an+2kn²+(2p-2k)n+(2q-k-p)=0∴2k=12p-2k=12q-k-p=0解得k=1/2...