Question 757444
Q:
find the value of  x in the sequence 1/2,  x,  1/8 if the sequence is an arithmetic progression and a geometric progression
--------------------------------------------------------------------
A:
If the sequence is an arithmetic progression,then
x - 1/2 = 1/8 - x
x + x = 1/8 + 1/2
2x = 5/8
x = {{{highlight(5/16)}}}
If the sequence is a geometric progression, then
{{{x/(1/2)}}} = {{{(1/8)/x}}}
{{{x^2}}} = {{{1/16}}}
x = ±{{{sqrt(1/16)}}} 
= {{{highlight(1/4)}}} OR {{{highlight(-1/4)}}}