Answer:
I think it is a I dont know
Answer:
to do everything u did. but backwards, OR to ask someone else the same question and if they get the same answer then yeah...
Answer:

Step-by-step explanation:
Given function is 
We need to find the value of 
For any function
if we want to find the value of
, we need to plug
in the function.
So, we will plug
in the function 

So, the value of
in the function
is 
I think the answer to this is 4 I think