CBSE Class 10 Answered
If sum of n terms of an AP is 2n^2+5n, then find its nth term?
Asked by | 27 Dec, 2012, 23:59: PM
Expert Answer
Sum of first n terms of AP, Sn = 2n2 + 5n
Now choose n =1 and put in the above formula,
First term = 2+5 = 7
Now put n=2 to get the sum of first two terms = 2x4 + 5x 2= 8 + 10 = 18
This means
first term + second term = 18
but first term =7 as calculated above
so, second term = 18-7 = 11
So common difference becomes, 11-7 = 4
So the AP becomes, 7, 11, 15, ....
nth term = a + (n - 1)d = 7 + (n-1)4 = 7 + 4n - 4 = 3 + 4n
Answered by | 28 Dec, 2012, 09:41: AM
Application Videos
-
Arithmetic Progression - 1
This video explains the concept of Arithmetic Progression, Solving Linear E... -
Sum of an n Terms of an A.P.
This video explains the concept of how to find the nth term of a Arithmetic... -
nth term of an A.P.
This video explains the concept of nth term of an Arithmetic Progression. -
Arithmetic Progression - 2
This video explains the concept of how to find an Arithmetic Progression. -
Nth term of an AP - 1
This video explains a case study based question covering the concept of ...
Concept Videos
-
Introduction to Arithmetic Progression
This video explains the identification of series which is mathematically kn... -
nth Term of an A.P.
Problems related to the calculation of nth term in an Arithmetic progressi... -
Determine terms of an arithmetic progression
Determine the terms of an arithmetic progression when given the number of t... -
Word Problems of A.P.
This video explains the concept of the nth term and the sum of the first n ... -
Introduction to Arithmetic Progression
This video explains the identification of series, mathematically known as A...
CBSE 10 - Maths
Asked by vishwanathhikkalagutti | 17 Jul, 2024, 07:25: AM
ANSWERED BY EXPERTCBSE 10 - Maths
Asked by lp9128437598 | 10 Jun, 2024, 10:34: AM
ANSWERED BY EXPERTCBSE 10 - Maths
Asked by sahooashutosh781 | 21 May, 2024, 13:26: PM
ANSWERED BY EXPERTCBSE 10 - Maths
Asked by purbashadebnath1980 | 09 Mar, 2024, 12:10: PM
ANSWERED BY EXPERTCBSE 10 - Maths
Asked by deepikaselvam2009 | 20 Feb, 2024, 20:57: PM
ANSWERED BY EXPERTCBSE 10 - Maths
Asked by keshavsinghalhapur | 16 Jan, 2024, 20:46: PM
ANSWERED BY EXPERTCBSE 10 - Maths
Asked by keshavsinghalhapur | 15 Jan, 2024, 10:56: AM
ANSWERED BY EXPERTCBSE 10 - Maths
Asked by durgauikey7000 | 08 Dec, 2023, 20:16: PM
ANSWERED BY EXPERTCBSE 10 - Maths
Asked by skandachiranjeevin | 06 Dec, 2023, 19:08: PM
ANSWERED BY EXPERTCBSE 10 - Maths
Asked by shaikhyakub9946 | 30 Nov, 2023, 11:50: AM
ANSWERED BY EXPERT
