Question

求数学题…已知数列{a1=1 a(n+1)=(4/an)+1-n 求通项公式

Answer 1

a(n+1)=4/an+1-n

(an)^2+a1an=4+an-an^2

a1=1

n^2+an=4+an-n^2

2n^2=4

n^2=2

n=1

an=n