Subtracting the equation (2) from equation (1), Then sum of its first 'n' terms of the geometric sequence a, ar, ar 2, ar 3. Sum of n Terms of Geometric Sequence Formula The n th term of the geometric sequence is, a n = a Its first term is a (or ar 1-1), its second term is ar (or ar 2-1), its third term is ar 2 (or ar 3-1). We have considered the sequence to be a, ar, ar 2, ar 3. Let us see each of these formulas in detail.
Here are the geometric sequence formulas. We will see the geometric sequence formulas related to a geometric sequence with its first term 'a' and common ratio 'r' (i.e., the geometric sequence is of form a, ar, ar 2, ar 3. We can also find the sum of infinite terms of a geometric sequence when its common ratio is less than 1. The geometric sequence formulas include the formulas for finding its n th term and the sum of its n terms.