Question

( A M>operatorname{GM} )
( frac{2008^{x}+2008^{-x}}{2} geqslantleft(2008^{x} cdot 2008^{-x}right)^{y_{2}} )
( Rightarrow frac{2008^{x}+2008^{-x}}{2} geq(1)^{1 / 2} )
( Rightarrow frac{2008^{x}+2008^{-x} 7}{2} )
( Rightarrow operatorname{Raye} . delta f quad f(x)=frac{2008^{x}+2008^{-x}}{2} )
is ( [1, infty) )

# 2008 008 Ra Range of f(x) = 2008* + 2008** is

Solution