Use geometric sequence formulas

Given the formula of a geometric sequence, either in explicit form or in recursive form, find a specific term in the sequence.


The geometric sequence a, left parenthesis, n, right parenthesis is defined by the following formula:
a, left parenthesis, n, right parenthesis, equals, 1, left parenthesis, minus, 2, right parenthesis, start superscript, n, minus, 1, end superscript
What is the fourth term in the sequence?
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3, slash, 5
  • a simplified improper fraction, like 7, slash, 4
  • a mixed number, like 1, space, 3, slash, 4
  • an exact decimal, like 0, point, 75
  • a multiple of pi, like 12, space, p, i or 2, slash, 3, space, p, i