Question

Find a formula for the nth term in this

arithmetic sequence:
a1 = 8, a2 = 4, a3 = 0, a4 = -4, ..

Answer 1

an = -4n +12

Explanation:

the nth term in this arithmetic sequence is : an = a1 + (n -1 )d

a1 = 8 d = a2-a1 = 4-8 = -4 ( common difrence)

an = 8 + (n -1 )(-4) = 8 - 4n +4

an = -4n +12