Y = f (x+4) This image is symmetrical about the origin.

Move the y=f(x) image to the left by 4 units.

Get an image with y=f(x+4).

∴ Move the y=f(x+4) image to the right by 4 units, namely

Get a y=f(x) image.

Y = f (x) is symmetric about O' (4,0).

The analytical formula of f(x) in the interval [4, +∞] is f(x)=4/x-x+3.

Take x

∴f(8-x)=4/(8-x)-(8-x)+3=4/(8-x)+x-5

∫y = f(x) is symmetric about o' (4,0).

∴f(x)=-f(8-x)=4/(x-8)-x+5

The analytical formula of ∴f(x) to r is

{4/x-x+3，(x≥4)

f(x)={4/(x-8)-x+5，(x & lt4)