badge image

Enroll For Free Now & Improve Your Performance.

×
User Icon
User Icon
User Icon
User Icon
User Icon

Thank you for registering.

One of our academic counsellors will contact you within 1 working day.

Please check your email for login details.
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: 12th pass

                        

If the sum of n terms of the AP are n²+n.show that it is an AP

3 years ago

Answers : (3)

Arun
24738 Points
							
If we put n= 1, then we get a1
Hence a1 = 1+ 1 = 2
When n= 2 , we get (a1 +a2)
Hence 
a1 +a= 4 + 2 = 6
Hence a2= 4
Now if n= 3, we get (a1 +a2 +a3 )
Hence 
a1 +a2 +a3  = 9+ 3 = 12
So
a3 = 12-2-4 =6
Similarily we get a1 ,a2 ,a3 ,a4 ,a5 ,a6 ,......
now if we see
a2 - a1 = a3 - a= a4 - a3 = 2= constant
HeHence we can say this forms an A.P.
3 years ago
sagar kumar
99 Points
							

Use the formula tn= a+(n-1)d =n2+n+1(sorry n2= n square) . To get square term here lets assume d=n . So a+n2-n=n2+n+1. So we can solve for a and it comes up to be 2n+1.

So by using a=2n+1 and d=n we can get nth term as n2+n+1. This is not the only assumed values,there may be much more . So how could you say that it is not possible??

3 years ago
Shaikh Muzzakir
45 Points
							Sum of the nth number is n^2+n. ....givenT1=1+1=2.   =A1....                        ( 1 )                             T2=4+2=6.    =A1+A2.                   ( 2 )                        A1+A2=6A2=4.               From ( 1 )T3=9+3=12.    = A1+A2+A3.         ( 3 )A1+A2+A3=12A3=6.              From( 2 )Hence, A2-A1=A3-A2=A4-A3 and so on...................The difference between them is d=2...........Therefore the given equation is A.P
						
2 years ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies


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

  • 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