A geometric sequence, also called geometric progression, is a number sequence with a common ratio between successive terms. A term in a geometric sequence can be found by multiplying the previous one by a non-zero and fixed number (a common ratio). 
•	geometric sequence:  a sequence with a common ratio between successive terms.
• the nth term, ,of a geometric sequence:
        
where, : nth term
: first term
r : common ratio
• the nth term, ,of a geometric sequence:
where, : nth term
: first term
r : common ratio






