Geometric sequences

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Now Playing:Geometric sequences – Example 1a
Examples
  1. Geometric sequence formula
    Consider the geometric sequence: 2, 6, 18, 54, … .
    1. Identify the common ratio.

    2. Determine the sixth term of the sequence.

    3. Which term in the sequence has a value of 39366?

Arithmetic sequences
Notes
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, tn{t_n} ,of a geometric sequence:
tn  =  t1rn1{t_n}\; = \;{t_1} \cdot {r^{n - 1}}
where, tn{t_n} : nth term
t1{t_1} : first term
r : common ratio