Question 454557
<font face="Times New Roman" size="+2">


Each function value is *[tex \Large \frac{1}{2}] the previous, so the function should contain the factor *[tex \Large \left(\frac{1}{2}\right)^x].  The function value when *[tex \Large x\ =\ 0] is 30 but we know that *[tex \Large \left(\frac{1}{2}\right)^0\ =\ 1], hence the function is:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ f(x)\ =\ 30\left(\frac{1}{2}\right)^x]


{{{drawing(
500, 500, -2,10,-2,31,
grid(1),
circle(0,30,0.1),
circle(1,15,0.1),
circle(2,7.5,0.1),
circle(3,3.75,0.1),
circle(4,1.875,0.1),
blue(graph(
500, 500, -2,10,-2,31,
30*(1/2)^x)))}}}


John
*[tex \LARGE e^{i\pi} + 1 = 0]
My calculator said it, I believe it, that settles it
<div style="text-align:center"><a href="http://outcampaign.org/" target="_blank"><img src="http://cdn.cloudfiles.mosso.com/c116811/scarlet_A.png" border="0" alt="The Out Campaign: Scarlet Letter of Atheism" width="143" height="122" /></a></div>
</font>