Question

Define the sum of an arithmetic sequence start by identifying the first and last number in the sequence

Answer 1

Answer:

Sn=n/2(a+last term)

Sn is sum of the numbers

a is the first term

n is the number of term

Answer 2

Step-by-step explanation:

Arthemetic progression :

the difference between two consecutive numbers are equal then the series in the arthemetic progression.

first number is called : a

last number is called : n

an = a + ( n - 1 )

sn = n/2( a + an )