Lesson Notes By Weeks and Term v4 - SHS 1

APPLICATIONS OF ALGEBRA

Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.

Subject: Additional Mathematics

Class: SHS 1

Term: 1st Term

Week: 12

Grade code: 1.1.2.LI.7

Strand code: 1

Sub-strand code: 2

Content standard code: 1.1.2.CS.1

Indicator code: 1.1.2.LI.7

Theme: MODELLING WITH ALGEBRA

Subtheme: APPLICATIONS OF ALGEBRA

Lesson Video

This page supports the lesson note with a companion video and a short classroom-ready summary.

For class groups and homework, share this lesson page so learners also get the summary, objectives, and full lesson context.

Performance objectives

Lesson summary

This lesson introduces the concept of composite functions. We will explore how functions can be combined, not by adding or multiplying them, but by applying one function to the result of another. Think of it like a production line: cocoa beans are harvested (first function), and then the harvested beans are fermented (second function). The final product depends on both processes happening in sequence. This concept of "function of a function" is a powerful tool in mathematics and has many real-world applications, from calculating currency exchange rates to understanding multi-step processes in science and economics.

Lesson notes

A. Refresher: What is a Function? A function is like a machine or a rule. It takes an input (usually `x`), performs an operation on it, and produces a single output (usually `f(x)` or `y`). Example: If `f(x) = 2x + 5`: If the input is `x = 3`, the output is `f(3) = 2(3) + 5 = 6 + 5 = 11`. If the input is `x = a`, the output is `f(a) = 2a + 5`.

B. Defining Composite Functions A composite function is created when you link two or more functions together in a sequence. The output of the first function becomes the input for the second function.

Imagine two machines: Machine `g`: Takes an input `x` and produces an output `g(x)`. Machine `f`: Takes the output from Machine `g`, which is `g(x)`, and uses it as its input to produce a final output `f(g(x))`.

This entire two-step process is a single composite function.

Evaluation guide