Step by step
The question
Question: find f(0) for f(x) = 4x + 1.
f(x) = 4x + 1
f(x) is read "f of x".
It is a rule, called a function.
A number goes in for x.
The rule gives one answer out.
f(x) = "f of x"
x goes in → an answer comes out
1 Put the number in
f(0) means: put 0 in place of every x.
We write it in brackets.
f(0) = 4(0) + 1
2 Times and divide
Times comes before plus.
Order: ( ) → x² √ → × ÷ → + −
4(0) = 4 × 0
4(0) means 4 times 0.
4 times 0 is 0.
= 0 + 1
3 Plus and minus
0 plus 1 is 1.
f(0) = 1
So f(0) = 1.
Let's look back.
First: put the number in.
Then: times and divide.
Last: plus and minus.
Answer
f(0) = 1