This can be a tricky question because this could be true or false depending how the Web Server is setup. For instance, with the Apache web server you do not need an index.html file as long as you have a index.htm file or an index.php file. So the answer could be false if you have one of the other files. Anyways, I think they mean an index file in general so the answer is true.
Sorry I don’t know the answer I am really sorry
Answer:

Explanation:
d(x) = -2x - 6
to find the inverse of a function, you need to follow these steps:
1. set d(x) = y
2. interchange the variables, so y becomes x and x becomes y
3. solve the equation for y
<u>step 1:</u> set d(x) = y
y = -2x -6
<u>step 2:</u> interchanging the variables
y = -2x - 6 turns into x = -2y - 6
<u>step 3:</u> solving for y
x = -2y - 6 < add 6 to both sides to get rid of it on the right
x + 6 = -2y < divide both sides by -2 to get y alone
x + 6 / -2 = 
-2y / -2 = y
= y
so the inverse of the function is 
1) You don't know if the source is reliable.
2) It is better to cite reliable sources so.