## Derivation of Sum of Finite and Infinite Geometric Progression

**Geometric Progression, GP**

Geometric progression (also known as geometric sequence) is a sequence of numbers where the ratio of any two adjacent terms is constant. The constant ratio is called the common ratio, *r* of geometric progression. Each term therefore in geometric progression is found by multiplying the previous one by *r*.

**Eaxamples of GP:**

- 3, 6, 12, 24, … is a geometric progression with
*r*= 2 - 10, -5, 2.5, -1.25, … is a geometric progression with
*r*= -1/2