Answer:
(a) and (b)
[tex]f(g(x)) = g(f(x)) = x[/tex]
(c) and (d)
[tex]f(g(x)) =-x + 8[/tex]
[tex]g(f(x)) = x + 8[/tex]
Step-by-step explanation:
Given
(a) to (d)
Required
Find f(g(x)) and g(f(x)) for each pair
For (a) and (b), we have:
[tex]f(x) = \frac{3}{x}[/tex]
[tex]g(x) = \frac{3}{x}[/tex]
Calculate f(g(x))
[tex]f(x) = \frac{3}{x}[/tex]
[tex]f(g(x)) = \frac{3}{g(x)}[/tex]
Substitute 3/x for g(x)
[tex]f(g(x)) = \frac{3}{3/x}[/tex]
Rewrite as:
[tex]f(g(x)) = 3/\frac{3}{x}[/tex]
[tex]f(g(x)) = 3*\frac{x}{3}[/tex]
[tex]f(g(x)) = x[/tex]
Since f(x) = g(x), then:
[tex]f(g(x)) = g(f(x)) = x[/tex]
For (c) and (d)
[tex]f(x) =x + 4[/tex]
[tex]g(x) =-x + 4[/tex]
Solving f(g(x)), we have:
[tex]f(x) =x + 4[/tex]
[tex]f(g(x)) =g(x) + 4[/tex]
Substitute [tex]g(x) =-x + 4[/tex]
[tex]f(g(x)) =-x + 4 + 4[/tex]
[tex]f(g(x)) =-x + 8[/tex]
Calculating g(f(x))
[tex]g(x) =-x + 4[/tex]
[tex]g(f(x)) = -f(x) + 4[/tex]
Substitute: [tex]f(x) =x + 4[/tex]
[tex]g(f(x)) = x + 4 + 4[/tex]
[tex]g(f(x)) = x + 8[/tex]
