Question

If the sum of the first n terms of an ap is 3n^2-2n find the ap and find its 19th

Answer 1

hope this will help you..

Answer 2

Answer:

we have to find the ap  and its 19th term

ATQ

Sum = n/2 [2a + (n-1)d]

3n^2 - 2n = n/2  [  2a + (n-1) d]

6n - 4 =  2a + (n-1)d

so ,

The nth term = 2a + (n-1)d = 6n - 4

 Thus 19th term

A(19) = 6*19 - 4

         =) 114-4 = 110

Hence the  19th term is 110

hop it helps you