The Louvre Museum as seen through the Louvre Pyramid glass in Paris, France. From the National Geographic book The 10 Best of Everything. Smithsonian Institution, Washington, D.C. The Smithsonian is the worldâs largest research and museum complex, with 19 museums and galleries, the National Zoological Park, and various research stations.
1 An arithmetic sequence is a sequence with the difference between two consecutive terms constant. 2  The difference is called the common difference. 3  A geometric sequence is a sequence with the ratio between two consecutive terms constant. 4  This ratio is called the common ratio.
A geometric sequence is a sequence such that each successive term is obtained from the previous term by multiplying by a fixed number called a common ratio. The sequence 5, 10, 20, 40, 80, .... is an example of a geometric sequence. The pattern is that we are always multiplying by a fixed number of 2 to the previous term to get to the next term. Be careful that you don't think that every sequence that has a pattern in multiplication is geometric.