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
        
If tn be the nth term of an AP and if t7=9, then the value of common difference that would make t1t2t7 least is____:
A)33/40     B)33/20    C)33/10
7 months ago

Answers : (1)

Arun
12359 Points
							
Dear Shiv
 
Since 
T1 T2 T7/9
= (9 -6d) (9-5d)
= 30 d² -99d +81
= 30 (d²- 99d/30) + 81
= 30 (d² - 33d/10 + 33²/20²) + 81 - 30* 33²/20²
= 30 ( d-33/20)² + 270/400
 
To make it least
 
d - 33/20 = 0
Hence
d = 33/20
 
 
Regards
Arun (askIITians forum expert)
 
7 months ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies

Get Extra Rs. 3,180 off

COUPON CODE: BCK2SKOOL


Course Features

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


Course Features

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


Get Extra Rs. 466 off

COUPON CODE: BCK2SKOOL

Ask Experts

Have any Question? Ask Experts

Post Question

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