Explain how to find the input given a function rule and output

So exg

input is the numbers that will  work so normally the range is all real numbers

make sure that you don't have any numbers that will make impossiblities exg
is the function is f(x)=3/x you can't use 0 for x because 3/0 is undifined and is impossible so

input is the numbers you put in
out put is what numbesr you get from the input exg

if function =f(x)+x+3 then
if input=3,5,6 then output is
(replaace 3,5,6 for x and solve)
output is 6,8,9