已知数列an满足a1=1/5,且当n>=2,n属于正整数时,有(a(n-1))/(an)=(2a(n-1)+1)/(1-2an)(1)求数列an的通项an(2)试问a1a2是否是数列an中的项?如果是,是第几项,如果不是,说明理由
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/19 14:20:13
![已知数列an满足a1=1/5,且当n>=2,n属于正整数时,有(a(n-1))/(an)=(2a(n-1)+1)/(1-2an)(1)求数列an的通项an(2)试问a1a2是否是数列an中的项?如果是,是第几项,如果不是,说明理由](/uploads/image/z/13270706-26-6.jpg?t=%E5%B7%B2%E7%9F%A5%E6%95%B0%E5%88%97an%E6%BB%A1%E8%B6%B3a1%EF%BC%9D1%2F5%2C%E4%B8%94%E5%BD%93n%3E%3D2%2Cn%E5%B1%9E%E4%BA%8E%E6%AD%A3%E6%95%B4%E6%95%B0%E6%97%B6%2C%E6%9C%89%28a%28n-1%29%29%2F%28an%29%3D%282a%28n-1%29%2B1%EF%BC%89%2F%281-2an%29%281%29%E6%B1%82%E6%95%B0%E5%88%97an%E7%9A%84%E9%80%9A%E9%A1%B9an%EF%BC%882%EF%BC%89%E8%AF%95%E9%97%AEa1a2%E6%98%AF%E5%90%A6%E6%98%AF%E6%95%B0%E5%88%97an%E4%B8%AD%E7%9A%84%E9%A1%B9%3F%E5%A6%82%E6%9E%9C%E6%98%AF%2C%E6%98%AF%E7%AC%AC%E5%87%A0%E9%A1%B9%2C%E5%A6%82%E6%9E%9C%E4%B8%8D%E6%98%AF%2C%E8%AF%B4%E6%98%8E%E7%90%86%E7%94%B1)
已知数列an满足a1=1/5,且当n>=2,n属于正整数时,有(a(n-1))/(an)=(2a(n-1)+1)/(1-2an)(1)求数列an的通项an(2)试问a1a2是否是数列an中的项?如果是,是第几项,如果不是,说明理由
已知数列an满足a1=1/5,且当n>=2,n属于正整数时,有(a(n-1))/(an)=(2a(n-1)+1)/(1-2an)
(1)求数列an的通项an
(2)试问a1a2是否是数列an中的项?如果是,是第几项,如果不是,说明理由
已知数列an满足a1=1/5,且当n>=2,n属于正整数时,有(a(n-1))/(an)=(2a(n-1)+1)/(1-2an)(1)求数列an的通项an(2)试问a1a2是否是数列an中的项?如果是,是第几项,如果不是,说明理由
(a(n-1))/(an)=(2a(n-1)+1)/(1-2an)
=>a(n-1)*(1-2an)=an*(2a(n-1)+1)
=>a(n-1)-2ana(n-1)=2ana(n-1)+an
=>a(n-1)-an=4ana(n-1)
=>1/an-1/a(n-1)=4
设bn=1/an
=>bn-b(n-1)=4,且b1=1/a1=5
=>bn=5+4(n-1)=4n+1
=>an=1/bn=1/(4n+1)
=>a1a2=1/5*1/9=1/45=1/(4*11+1
=>n=11
=>第十一项
已知数列{an} 满足a1=1/5,且当n>1,n∈N+时,an—1/an=2an—1+1/1—2an(1)求证:数列{1/an} 为等差数列;
已知数列an中满足a1=1且当n.=2时,2an*a*(n-1)+an-a(n-1)=0,求通项公式an
已知数列an满足an=1+2+...+n,且1/a1+1/a2+...+1/an
已知数列{an}满足:an+1=an+n,且a61=2002,则a1等于
已知数列{an}满足3a(n+1)=2an-4,且a1=1/5,求an
已知数列an满足a1=1/5,且当n>=2,n属于正整数时,有(a(n-1))/(an)=(2a(n-1)+1)/(1-2an)(1)求数列an的通项an(2)试问a1a2是否是数列an中的项?如果是,是第几项,如果不是,说明理由
已知数列an满足an+1/an=n+2/n且a1=1,则an=
已知数列{an}满足a1=4/3,且an+1=4(n+1)an/3an+n
已知数列{An}满足A1=1/5,且当n>1,n∈N*时,有a(n-1)/an=2a(n-1)+1/1-2an
已知数列{an}满足(n+1)an+1=an+n,且a1=2,则a2010=?
已知数列{an}满足a(n+1)=an+3n+2,且a1=2,求an=?
已知数列an满足a(n+1)=an+3n+2,且a1=2,求an
已知数列{an}满足an+1=an+3n+2,且a1=2,求an.
已知数列{an}满足条件a1=3,且a( n+1)-an=(20)^n+n,求通项公式已知数列{an}满足条件a1=3,且a( n+1)-an=(2)^n+n,求通项公式
五道高一数学题,在线等1.数列{an}满足:a1=2.当n≥1时,有a(n+1)=an/2+3,求{an}的通项公式an2.已知a1=1,a2=3且a(n+2)-2a(n+1)+an=a,求an3.数列{an}满足a1=1,a(n+1)=4an+(3n+1),求an4.数列{an}满足递推关系:an=a(n-2)+2,且a1=
已知数列{an}满足a0=1,an=a0+a1+…+an-1(n≥1),则当n≥1时,an= ( )
已知数列{An}满足A1=1/5,切且当n>1,n∈正整数时,A(n-1)/An=[2A(n-1)+1]/(1-2An),⑴求证:数列{1/An}为等差数列;⑵试问A1·A2是否是数列{An}中的项?如果是,是第几项?如果不是,请说明理由.注:()中的
已知数列{Sn}的通项公式Sn=n^2-21*n/2(n属于N*),又设数列{an}满足:a1=S1,当n大于等于2时,an=Sn-Sn-1又设数列{an}满足a1=S1,当n≥2时,an=Sn-Sn-1.bn=1/(2n+1)+k,且有bn<an,(m,n∈N*)恒成立,求实数k的取值范围