It is known that the quadratic function f (x) is an increasing function in the domain of definition (0, ∞), and f (XY) = f (x) + F (y). F (2) = 1 1 to prove f (8) = 3
Because f (XY) = f (x) + F (y)
f(8)=f(2*4)=f(2)+f(4)=f(2)+f(2*2)=f(2)+f(2)+f(2)=3*f(2)
And because f (2) = 1
So f (8) = 3 * f (2) = 3
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