Home
Class 11
MATHS
Find the sum to n terms of the G.P.sqrt7...

Find the sum to n terms of the G.P.`sqrt7,sqrt21,3sqrt7…`

Text Solution

Verified by Experts

`a=sqrt7, r=sqrt21/sqrt7=sqrt3`
`S_n=a (r^n-1)/r-1=sqrt7[(sqrt3)^n-1]/sqrt3-1 = .sqrt7[(sqrt3)^n-1](sqrt3+1))/(sqrt3-1)(sqrt3+1)=sqrt7/2(sqrt3+1)[3^n/2-1]`
Promotional Banner

Topper's Solved these Questions

  • RELATIONS AND FUNCTIONS

    V PUBLICATION|Exercise QUESTIONBANK|79 Videos

  • SETS

    V PUBLICATION|Exercise QUESTION BANK|116 Videos

Similar Questions

Explore conceptually related problems

Find the sum of first 20 terms of the GP sqrt3,2sqrt3,4sqrt3,8sqrt3 ,……..

Find the sum to 15 terms of the AP 3,7,11,……

Find the sum to n terms of the G.P. x^3,x^5,x^7,…(xne+-1)

Find the sum to n terms of the G.P. 1,-a,a^2,-a^3,...(ane-1)

Find the sum of n terms of the series 7+77+777+..

Find the sum to n terms of the sequence 7,77,777,7777,…….

Find the sum to n terms of this series. 1times4+3times7+5times10+…….

Find the sum of the 1^(st) n terms of the series 3+7+13+21+31+ …

Find the sum of the first n terms of the series : 3+7+13+21+31+. . .

Find the sum of the first n terms of the arithmetic sequence 1/n,3/n,5/n,7/n ,.......

V PUBLICATION-SEQUENCES AND SERIES-QUESTIONBANK
  1. For what value of x, the numbers -2/7,x.-7/2 are in G.P ?

    Text Solution

    |

  2. Find the sum to 20 terms of 0.15,0.015,0.0015,..

    Text Solution

    |

  3. Find the sum to n terms of the G.P.sqrt7,sqrt21,3sqrt7…

    Text Solution

    |

  4. Find the sum to n terms of the G.P. 1,-a,a^2,-a^3,...(ane-1)

    Text Solution

    |

  5. Find the sum to n terms of the G.P.x^3,x^5,x^7,…(xne+-1)

    Text Solution

    |

  6. Evaluate underset(K=1)overset11sum(2+3^K)

    Text Solution

    |

  7. The sum of the first three terms of a GP is (39)/(10) and their produc...

    Text Solution

    |

  8. How many terms of GP 3,3^2,3^3,..... are needed to give the sum 120?

    Text Solution

    |

  9. The sum of the first three terms of a G. P is 16 and the sủm of the ne...

    Text Solution

    |

  10. Given.a G. P. with a=729 and 7^ (th) term 64, determine S7 ?

    Text Solution

    |

  11. The sum of the first two terms of a GP Is -4 and the fifth term is 4 t...

    Text Solution

    |

  12. If the 4 ^(th), 10^(th) and 16^ (th) terms of a G . P are x, y and z ...

    Text Solution

    |

  13. Find the sum to n terms of the series: 8, 88, 888,…..

    Text Solution

    |

  14. Find the sum of the products of the corresponding terms of the sequenc...

    Text Solution

    |

  15. Find four numbers forming a geometric progression.in which the third t...

    Text Solution

    |

  16. If the p^th,q^th and r^th terms of a GP are a,b,c respectively, show t...

    Text Solution

    |

  17. If the first and the n^( th) term of a .G. P are a and b, respectivel...

    Text Solution

    |

  18. Show that the ratio of the sum of first n terms of a G. P to the sum o...

    Text Solution

    |

  19. If a, b, c and d are in G . P, show that (a^2+b^2+c^2)(b^2+c^2+d^2)=(a...

    Text Solution

    |

  20. Insert two numbers between 3 and 81 iso that the resulting sequence is...

    Text Solution

    |