MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping
Menu
Grade: 11
        
Find the Sum of n numbers of this series/sequence. Please answer this quickly...
1*n + 2*(n-1) + 3*(n-2) + … + n*1. Find Sn
 
one month ago

Answers : (2)

Vikas TU
9095 Points
							
Dear student 
it is summation of r(n-r+1) where r varies from 1 to n;
SUM => ( (n+1)r - r^2 ) = (n+1)(n)(n+1)/2 - (n)(n+1)(2n+1)/6
 
Hope this helps 
Good Luck 
one month ago
Arun
22777 Points
							
Dear student
 
Tn = ∑(r belongs from 1 to n) (r) ( n – r+ 1))
 
Tn = ∑ ( nr – r^2 + r)
 
now put limit
 
Hope it helps
one month ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies


Course Features

  • 728 Video Lectures
  • Revision Notes
  • Previous Year Papers
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Test paper with Video Solution


Course Features

  • 731 Video Lectures
  • Revision Notes
  • Test paper with Video Solution
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Previous Year Exam Questions


Ask Experts

Have any Question? Ask Experts

Post Question

 
 
Answer ‘n’ Earn
Attractive Gift
Vouchers
To Win!!! Click Here for details