Question

Find the first two terms of sequence for which sequence of Sn is given as n²(n+1)

Answer 1

Answer:

Step-by-step explanation:

Sn = n²(n+1)

∴ If we put  n = 1  then ,

S1 = 1² ( 1 + 1 )

∴ S1 =  2

ALSO  S1  =  a1  =  first term of the AP = 2

∴ first term of AP is  2

Again if we put  n = 2 then

S2 = 2² ( 2 + 1 ) = 12

∵ a2 = second term of AP is =  S2 - S1

∴ a2 = second term of AP is = 12 - 2 = 10

∴ the AP is 2 , 12 , ..............