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
Atish Dutta Grade: 11
        
if a1=2 and an-an-1=2n(n>=2), find the value of a1+a2+a3+.....+a20.
one year ago

Answers : (1)

bhawani
33 Points
										
420
tn= 2 + { 4 + 6 + 8 + 10 + – – – –   + 19 terms}
=2 + 19/2{2.4 + (19 – 1 )2}
2 + 19/2{ 8 + 36}
=420
one year ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies
  • Complete JEE Main/Advanced Course and Test Series
  • OFFERED PRICE: Rs. 15,000
  • View Details

Ask Experts

Have any Question? Ask Experts

Post Question

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