1.若数列an满足:a1=1,a(n+1)=2an(n∈N+),则a5=?前8项的和S8=?2.等差数列an的前n项和为Sn,且S3=6,a1=4,则公差d?3.设等比数列an的前n项和为Sn ,若S6/S3=3,则S9/S6=4.已知等比数列an的公比为正数,且a3*a9=2a5^2,a2=1,
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![1.若数列an满足:a1=1,a(n+1)=2an(n∈N+),则a5=?前8项的和S8=?2.等差数列an的前n项和为Sn,且S3=6,a1=4,则公差d?3.设等比数列an的前n项和为Sn ,若S6/S3=3,则S9/S6=4.已知等比数列an的公比为正数,且a3*a9=2a5^2,a2=1,](/uploads/image/z/1740853-37-3.jpg?t=1.%E8%8B%A5%E6%95%B0%E5%88%97an%E6%BB%A1%E8%B6%B3%EF%BC%9Aa1%3D1%2Ca%28n%2B1%29%3D2an%28n%E2%88%88N%2B%29%2C%E5%88%99a5%3D%3F%E5%89%8D8%E9%A1%B9%E7%9A%84%E5%92%8CS8%3D%3F2.%E7%AD%89%E5%B7%AE%E6%95%B0%E5%88%97an%E7%9A%84%E5%89%8Dn%E9%A1%B9%E5%92%8C%E4%B8%BASn%2C%E4%B8%94S3%3D6%2Ca1%3D4%2C%E5%88%99%E5%85%AC%E5%B7%AEd%3F3.%E8%AE%BE%E7%AD%89%E6%AF%94%E6%95%B0%E5%88%97an%E7%9A%84%E5%89%8Dn%E9%A1%B9%E5%92%8C%E4%B8%BASn+%2C%E8%8B%A5S6%2FS3%3D3%2C%E5%88%99S9%2FS6%3D4.%E5%B7%B2%E7%9F%A5%E7%AD%89%E6%AF%94%E6%95%B0%E5%88%97an%E7%9A%84%E5%85%AC%E6%AF%94%E4%B8%BA%E6%AD%A3%E6%95%B0%2C%E4%B8%94a3%2Aa9%3D2a5%5E2%2Ca2%3D1%2C)
1.若数列an满足:a1=1,a(n+1)=2an(n∈N+),则a5=?前8项的和S8=?2.等差数列an的前n项和为Sn,且S3=6,a1=4,则公差d?3.设等比数列an的前n项和为Sn ,若S6/S3=3,则S9/S6=4.已知等比数列an的公比为正数,且a3*a9=2a5^2,a2=1,
1.若数列an满足:a1=1,a(n+1)=2an(n∈N+),则a5=?前8项的和S8=?
2.等差数列an的前n项和为Sn,且S3=6,a1=4,则公差d?
3.设等比数列an的前n项和为Sn ,若S6/S3=3,则S9/S6=
4.已知等比数列an的公比为正数,且a3*a9=2a5^2,a2=1,则a1=
5.等比数列an的公比q>0,已知a2=1,a(n+2)+a(n+1)=6an,则an的前4项和S4
6.等差数列an的公差不为零,首项a1=1,a2是a1和a5的等比数列,S10=
7.设a1=2,a(n+1)=1/a(n+1),bn=(an)+2/(an)-1的绝对值,n∈N+,则数列bn的通项公式
7.设a1=2,a(n+1)=2/a(n+1),bn=(an)+2/(an)-1的绝对值,n∈N+,则数列bn的通项公式
1.若数列an满足:a1=1,a(n+1)=2an(n∈N+),则a5=?前8项的和S8=?2.等差数列an的前n项和为Sn,且S3=6,a1=4,则公差d?3.设等比数列an的前n项和为Sn ,若S6/S3=3,则S9/S6=4.已知等比数列an的公比为正数,且a3*a9=2a5^2,a2=1,
1.16 255
2.-2
3.7/3
4.根号2/2
5.3.5
6.100
7.有问题吧.
1.a5=16 s8=255
2.-2
3.7/3
4.√2/2
5.3.5
6.100