Question

wirte the formula to find the sum of n term​

Answer 1

HERE IS UR ANSWER DEAR,

Sum of N Terms Formula

Sum of N Terms Formula It is equal to n divided by 2 times the sum of twice the first term – 'a' and the product of the difference between second and first term-'d' also known as common difference, and (n-1), where n is numbers of terms to be added.

Answer 2

Formula to find Nth term:

an=a1 + (n−1) d

a1 = First term

common difference = d

Example: 2, 4, 6, 8, 10 in this question "d" = 2 because there is a gap of 2 numbers from each number

and Nth term = an

Examples:

question:

2, 4, 6, 8... (... means soo on) find the 20th term if the following AP (arithmetic progression)

Answer:

1) Find the common difference:

  d = 2

Formula:

  an=a1 + (n−1) d

Plug in the terms:

=> a1 = 2

=> an = 20 (we have to find the nth term)

=> n = 20 (the number which you want to find)

=> d = 2

a20 = 2 + (20 - 1) . 2

Simplify:

a20 = 2 + (20 - 1) . 2

=> 2 + 19 x 2

=> 2 + 38

=> 40

Nth term = 40

Hope This Helps You

Have a Nice Day :)