Question

Determine the Common Difference of the arithmetic sequence in which \large a_1=3 and \large a_4=15

Answer 1

d = 4

Explanation:

the nth term of an arithmetic sequence is

`a_(n)` = a₁ + (n - 1)d

a₁ is the first term , d the common difference, n the term number

given a₄ = 15 and a₁ = 3 , then

a₁ + 3d = 15 , that is

3 + 3d = 15 ( subtract 3 from both sides )

3d = 12 ( divide both sides by 3 )

d = 4