已知数列{ an }的前n项和为sn,a1=1,sn+1=sn+an+6求数列{ an }的同项请讲解这一步s(n+1) = sn + a(n+1) = sn+an+6,a(n+1) = an + 6

已知数列{ an }的前n项和为sn,a1=1,sn+1=sn+an+6求数列{ an }的同项请讲解这一步s(n+1) = sn + a(n+1) = sn+an+6,a(n+1) = an + 6
已知数列{ an }的前n项和为sn,a1=1,sn+1=sn+an+6求数列{ an }的同项
请讲解这一步s(n+1) = sn + a(n+1) = sn+an+6,a(n+1) = an + 6

已知数列{ an }的前n项和为sn,a1=1,sn+1=sn+an+6求数列{ an }的同项请讲解这一步s(n+1) = sn + a(n+1) = sn+an+6,a(n+1) = an + 6
a1=1
s1=1
s(n+1) = sn + a(n+1) = sn+an+6, a(n+1) = an + 6
是个等差数列
an = 1 +6*(n-1) = 6n - 5

Sn+1-Sn=an+1=an+6 所以an+1-an=6 该数列为等差数列an=1+6(n-1)=6n-5

sn+1=sn+an+6
sn+1-sn=an+6
an+1=an+6
a[n+1]-an=6 等差数列d=6 a1=1
an=a1+(n-1)d=6n-5

Sn+1-sn=an+6
an+1=an+6
an等差数列
an=6n-5