Question

An arithmetic sequence has a first term equal to 8. Also, its 16th term is twice its 8th term. Find a formula for the n th term, T n , of this sequence.

Answer 1

T(n) = 7+n

Explanation:

A.P. Formula: a(n) = a + (n-1)d

Since a = 8 (given),

and we know 2*[T(8)] = T(16)

We may set up an equation to find d/

2(8+(8-1)d) = 8+(16-1)d

d = 1

Therefore, T(n) = 8 + (n-1)(1) = 7+n