Question

The nth term of an AP is 12-4n. Find the first term and the common difference.

Answer 1

first term is 8 and common difference d is -4

Explanation:

nth term of an arithmetic sequence is: aₙ=12-4n

First term is putting n=1:

aₙ=12-4n

a₁=12-4(1)

a₁=12-4

a₁=8

So, first term a₁= 8

Now finding second term to find common difference

Second term is: n=2

aₙ=12-4n

a₂=12-4(2)

a₂=12-8

a₂=4

So, second term is: 4

The common difference is: a₂-a₁= 4-8 = -4

So, first term is 8 and common difference d is -4 if nth term is 12-4n