Question 927781
{{{y=2^(x-1)}}}=> this is a geometric sequence


In general we can write a geometric sequence like this:

{a, ar, ar^2, ar^3, ... }

where:

    {{{a}}} is the first term, and
    {{{r}}} is the factor between the terms (called the "common ratio")

Note: {{{r}}} should not be {{{0}}}.

    When {{{r=0}}}, we get the sequence {a,0,0,...} which is {{{not}}} geometric

And the rule is:

{{{a[n] = ar^(n-1)}}}

(We use "n-1" because ar^0 is the 1st term)

in your case {{{y=2^(x-1)}}}=> {{{a=1}}} and {{{r=2}}}


{{{ graph( 600, 600, -10, 10, -10, 10, 2^(x-1)) }}}