write a formula

Question

Write a formula for the general term (the nth term) of the arithmetic sequence. Then use the formula for a_n to find a₃₀, the 30th term for the sequence. 

 

1, 5, 9, 13, ....

a_{n = ?}

Answer 1

For an arithmetic sequence:

 

a_n = a₁ + (n - 1)d, where a₁ = first term, n = number of terms, d = common difference

 

a₃₀ = 1 + 29(4)

a₃₀ = 1 + 116

a₃₀ = 117