Hello!
The answers are:
a) The name of function is f.
b) Independent variable : x , dependent variable : y/f(x)
c) The rule that assings exactly one output to the very input is called "function".
d) [tex]f(4)=\frac{3}{4+2}=\frac{3}{7}[/tex]
Why?
Usually, the name of a function [tex]f(x)[/tex] is what is out of the parentheses, so the name of the function is "f".
The independent variable of a function is the variable we assign the different values, so, for this case, the independent variable is designated with the letter "x"
The dependent variable is the function itself, it's also called "y", it's called "dependent" variable because its values will always depend on the "independent variable"
A function is a rule that states that there is exactly one output (range value) to the very input (domain value). A function only exists when there is exactly one output value (range) for each input (domain), if there is more than one output for each input, the function does not exist.
Evaluating a function consists of assign values to the independent variable(x), hence:
[tex]f(4)=\frac{3}{4+2}=\frac{3}{7}[/tex]
Have a nice day!