4 f (2) = radical sign (4 f (1)) = radical sign ([2 f (1)] 2) = 2 f (1).

4^f(2)=2^2f(2)=2^f( 1)

2f(2)=f( 1)

f(x)=x^a

2*2^a= 1

a=- 1

f(x)= 1/x

(2)H(x)= 1/x+x/a

a & lt=0

Decreasing by (0,2)

a & gt0

reclassification