a)
f(x) is the same as y
y=1/3 x +4
to find inverse, swap and x and y:
x=1/3 y + 4
x-4= 1/3 y
(x-4) x 3 = y
3x -12= y
the inverse(g(x)), is: 3x-12
b) if f(x) and g(x) are inverses of each other, than (f о g)(x) will end up with just "x"
(f о g)(x)=x
(f о g)(x)= f(g(x))
(f о g)(x)= f(3x-12)
(f о g)(x)= 1/3(3x-12)+4
(f о g)(x)= (3x-12)/3 +4
(f о g)(x)= x-4+4
(f о g)(x)= x
c)
You will find that the graphs are mirror images of each other
the graph for f(x) is an oblique line that passes through the points(-12,4)
the graph for g(x) is an oblique line that passes through the points(4,-12)