Razão PG (q)
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
About this calculator
The geometric progression ratio calculator (q) computes the ratio between the second term (a₂) and the first term (a₁) of a geometric sequence. The formula used is q = a₂ ÷ a₁, representing how many times the initial term is multiplied to get the next element in the sequence.
This tool is useful for solving math exercises involving geometric progressions, such as predicting future terms, verifying sequence patterns, or analyzing exponential behavior. Simply input the first two ordered terms of the sequence.
Important considerations: The first term (a₁) cannot be zero, as division by zero is undefined. Terms must be entered in the correct sequence order. A negative ratio indicates alternating positive and negative terms in the sequence.
Frequently asked questions
What is a geometric progression?
It's a numerical sequence where each term is obtained by multiplying the previous one by a constant called the ratio (q).
How does the ratio affect the sequence?
If q > 1: the sequence grows exponentially. If 0 < q < 1: it decreases. If q < 0: terms alternate between positive and negative.
Can I use this calculator with negative terms?
Yes, as long as both terms are in sequence order. The ratio can be negative, indicating alternating signs.
What if the first term is zero?
Division by zero is not allowed. The sequence would not qualify as geometric in this case.