9 m
c) radius =
diameter =

Answer is in the file below

is.gd/qKzpBU

radius is 9 m and diameter is 2 x9 = 18

(1,4) is on graph of f(x)

f(1) = 4

so 1/4 f(x)

1/4 f(1)

1/4. ×4

1

so point for function 1/4. f(x) is (1,1)