Answer:
Part 1) The graph in the attached figure N 1
Part 2) The graph in the attached figure N 2
Part 3) The graph in the attached figure N 3
Part 4) The graph in the attached figure N 4
Step-by-step explanation:
Part 1) we have
[tex]f(x)=20-x[/tex]
Find the inverse
Let
y=f(x)
[tex]y=20-x[/tex]
Exchange the variables x for y and y for x
[tex]x=20-y[/tex]
isolate the variable y
[tex]y=-x+20[/tex]
[tex]f^{-1}(x)=y[/tex]
[tex]f^{-1}(x)=-x+20[/tex] ------> inverse function
see the attached figure N 1
Part 2) we have
[tex]f(x)=\frac{x}{x-20}[/tex]
Find the inverse
Let
y=f(x)
[tex]y=\frac{x}{x-20}[/tex]
Exchange the variables x for y and y for x
[tex]x=\frac{y}{y-20}[/tex]
isolate the variable y
[tex]y=\frac{20x}{x-1}[/tex]
[tex]f^{-1}(x)=y[/tex]
[tex]f^{-1}(x)=\frac{20x}{x-1}[/tex] ------> inverse function
see the attached figure N 2
Part 3) we have
[tex]f(x)=20x[/tex]
Find the inverse
Let
y=f(x)
[tex]y=20x[/tex]
Exchange the variables x for y and y for x
[tex]x=20y[/tex]
isolate the variable y
[tex]y=\frac{1}{20}x[/tex]
[tex]f^{-1}(x)=y[/tex]
[tex]f^{-1}(x)=\frac{1}{20}x[/tex] ------> inverse function
see the attached figure N 3
Part 4) we have
[tex]f(x)=\frac{x+20}{x}[/tex]
Find the inverse
Let
y=f(x)
[tex]y=\frac{x+20}{x}[/tex]
Exchange the variables x for y and y for x
[tex]x=\frac{y+20}{y}[/tex]
isolate the variable y
[tex]y=\frac{20}{x-1}[/tex]
[tex]f^{-1}(x)=y[/tex]
[tex]f^{-1}(x)=\frac{20}{x-1}[/tex] ------> inverse function
see the attached figure N 4