Answer:
The value of f(3) = 28.26
Step-by-step explanation:
You have to do is to substitute r = 3 into the function :
[tex]f(r) = 3.14 \times {r}^{2} [/tex]
[tex]f(3) = 3.14 \times {3}^{2} [/tex]
[tex]f(3) = 3.14 \times 9[/tex]
[tex]f(3) = 28.26[/tex]
