Question

The sum of the 1st n terms, Sn, of a particular arithmetic progression is given by Sn= 4n²+3n. Find the 1st term and the common difference.

Answer 1

Answer:

1st term = 7 and

common difference = 8

Step-by-step explanation:

given,

Sn = 4n^2+3n

Soo...

S1 =( term 1) = 4(1)^2 + 3(1)

= 4(1) + 3

= 4 + 3

=7

S2 = (term 1 + term 2)

= 4(2)^2 + 3(2)

= 4(4)+6

= 16+6

=22

S2 = term 1 + term 2

=7 + t2 = 22

= t2 = 22 - 7

= t2 = 15

common difference = t2 - t1

= 15 - 7

= 8..

hence...

term 1 = 7.

common difference = 8..