How do you use the geometric sequence of numbers 1, 2, 4, 8,…to find r, the ratio between 2 consecutive terms?

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Answer 1 · 2015-11-05T19:46:56

#r = 2#
See explanation.

Let any term in a geometric sequence be #a#

Let the i'th term be #a_i#

Let a constant be k

Let the geometric ratio be r

The #a_i = kr^i#

#a_1 = kr = 1#
#a_2=kr^2 = 2#
#a_3 = kr^3=4#

So #a_(i+1)/a_(i) = (kr^(i+1))/(kr^i) = r#

So #a_2/a_1 = 2/1 =r=2#