Algebra · Functions
Chapter 1 · 4
The idea
Function notation
Why f(x) is a machine's output, not a multiplication — evaluating f(3), reading f(x) = k as an equation to solve, and keeping inputs and outputs straight.
A full journey — read it, play with it, work it, then earn real exam marks. Everything stays on the timeline below.
In this lesson — start anywhere
Algebra · Functions
Function notation
Why f(x) is a machine's output, not a multiplication — evaluating f(3), reading f(x) = k as an equation to solve, and keeping inputs and outputs straight.
Why it works
A named machine
throws more students than the maths it contains, for one reason: it looks like a multiplication — " times " — and it absolutely isn't. One idea fixes the entire topic. names a machine: feed a number into the slot, and the recipe on the right says what comes out.Evaluating: substitute everywhere
To evaluate, put the input into every in the recipe:Keep reading — free
The rest of the explanation, plus 2 worked examples you step through move by move.
Start freeTakes a minute — no card.