I can eyeball points (1/2, 8), (1,4), (2,1), (3,1/4)
The pattern is each increment of 1/2 in x divides by two.
[tex]f(x) = (\frac k 2)^{2x} = \frac{k}{4^x} [/tex]
Any of the points give k=16
[tex]f(x) = 16( 4 ^{-x} ) = 4^{2-x} [/tex]
Check: x=1/2 4^(3/2)=2^2=8 good
x=1 4^(2-1)=4 good
x=2 4^(2-2)=1 good
x=3 4^(2-3)=1/4 good
