已知函数f(X9)=lnx-x+1(x[1,+无穷大)),数列{an}满足a1=e,(a(n+1))/an=e 1求数...已知函数f(X9)=lnx-x+1(x[1,+无穷大)),数列{an}满足a1=e,(a(n+1))/an=e1求数列{an}的通项公试an?2求:f(a1)+f(a2)+f(a3)+…f(an),3
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已知函数f(X9)=lnx-x+1(x[1,+无穷大)),数列{an}满足a1=e,(a(n+1))/an=e 1求数...已知函数f(X9)=lnx-x+1(x[1,+无穷大)),数列{an}满足a1=e,(a(n+1))/an=e1求数列{an}的通项公试an?2求:f(a1)+f(a2)+f(a3)+…f(an),3
已知函数f(X9)=lnx-x+1(x[1,+无穷大)),数列{an}满足a1=e,(a(n+1))/an=e 1求数...
已知函数f(X9)=lnx-x+1(x[1,+无穷大)),数列{an}满足a1=e,(a(n+1))/an=e
1求数列{an}的通项公试an?2求:f(a1)+f(a2)+f(a3)+…f(an),3求证:1乘2乘3乘…乘n小于等于en^(n(n-1)/2)
已知函数f(X9)=lnx-x+1(x[1,+无穷大)),数列{an}满足a1=e,(a(n+1))/an=e 1求数...已知函数f(X9)=lnx-x+1(x[1,+无穷大)),数列{an}满足a1=e,(a(n+1))/an=e1求数列{an}的通项公试an?2求:f(a1)+f(a2)+f(a3)+…f(an),3
1 (a(n+1)/an=e
所以 an为等比数列
an=a1*d^(n-1)=e*e^(n-1)=e^n
2 f(a1)+f(a2)+f(a3)+...+f(an)=(1-e+1)+(2-e²+1)+(3-e³+1)+.(n-e^n+1)
=2+3+4+...+(n+1)-(e²+e³+.+e^n)
=(2+n+1)*n/2-e²*(e^(n-1)-1)/(e-1)
3 那个是en么 en^(n(n-1)/2)?