__Example 2__

Functions f and g are defined by $f:x\mapsto x-1$ and $g:x\mapsto \frac{3-x}{x+4}$ . Find

(a) the value of gf(3),

(b) the value of fg(-1 ),

(c) the composite functions fg,

(d) the composite functions gf,

(e) the composite functions ${g}^{2}$ ,

(f) the composite functions ${f}^{2}$ .