Question

Which of the following is the correct relation between nth term and the sum to n terms of an AP ​

Answer 1

General Form of AP a, a + d, a + 2d, a + 3d, . . .

Nth term of AP an = a + (n – 1) × d

Sum of n terms in AP S = n/2[2a + (n − 1) × d]

Sum of all terms in a finite AP with last term as 'l' n/2(a + l)