Step by step
The question
Question: find f(3) in this table of f.
f(3) = ?
1 Look at the table
The table shows f.
Each x on top has its f(x) right under it.
For example, f of 1 is 4.
x: top row
f(x): right under its x
2 Read f(3)
The number in the brackets is the x.
Here x is 3.
f(3): x = 3 → f(x) = ?
Careful!
f of 3 does not mean f(x) is 3.
The 3 in the brackets is an x.
So we start at 3 on the x row.
Careful: f(3): start at x = 3, not at f(x) = 3
Find 3 in the x row.
Right under it is 10.
So f(3) = 10.
f(3) = 10
3 Check
Let's check the other way.
The 10 in the bottom row sits under x = 3.
So the answer is right!
column: x = 3, f(x) = 10
Let's look back.
First: look at the table.
Then: read f(3).
Last: check.
Answer
f(3) = 10