The domain of this function is not symmetrical about the origin, so the function is odd and even.

(2)4-x？ ≥0，-2≤x≤2，

So x-3 < 0,

∴f(x)=√(4-x？ )/(|x-3|-3)= √(4-x？ )/(3-x-3)= √(4-x？ )/(-x)，

F(-x)= √(4-x？ )/x，f(-x)=-f(x)，

This function is an odd number function.

(3)f(x)= 1/(2^x- 1)+ 1/2=(2^x+ 1)/[2(2^x- 1)]

2 x- 1 ≠ 0, x≠0, the domain is symmetric about the origin.

F (-x) = (2 (-x)+1)/[2 (2 (-x)-1)] ... The numerator denominator is the same as 2 x.

=( 1+2^x)/[2( 1-2^x)]=- f(x)、

This function is an odd number function.