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Mathematics is a compulsory course for senior one, Chapter 2 Function.
The function y is defined on r = f (x), and f (0) is not equal to 0. When x >; 0.f(x)> 1, and f (x+y) = f (x) × f (y) for any real number x, y/. 0. If there is 0 1, find the value range of x.

Solution: Let x=y=0, then f(0)=f(0)f(0).

∫f(0)≠0

∴f(0)= 1

Let y=-x, then f(x-x)=f(x)(-x)= 1.

∴f(-x)= 1/f(x)

∵x & gt; 0.f(x)> 1

∴-x<; 0

∴0<; f(x)& lt; 1

That is, when x

(2) make X 1

f(x 1)-f(x2)= f(x 1)-f(x2-x 1+x 1)

= f(x 1)-f(x2-x 1)f(x 1)

= f(x 1)( 1-f(x2-x 1))

∵x2-x 1 & gt; 0

∴f(x2-x 1)>; 1

∴f(x 1)<; f(x2)

It's adding functions.

(3)f(x^2)*f(2x-x^2+2)>; 1

f(x^2+2x-x^2+2)>; f(0)

It's adding functions.

∴x^2+2x-x^2+2>; 0

x & gt- 1