APPLICATIONS OF ALGEBRA
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Subject: Additional Mathematics
Class: SHS 1
Term: 1st Term
Week: 15
Grade code: 1.1.2.LI.1
Strand code: 1
Sub-strand code: 2
Content standard code: 1.1.2.CS.1
Indicator code: 1.1.2.LI.1
Theme: MODELLING WITH ALGEBRA
Subtheme: APPLICATIONS OF ALGEBRA
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This lesson introduces two powerful shortcuts in algebra: the Remainder Theorem and the Factor Theorem. We often work with complex polynomial expressions in fields like engineering, economics, and even in planning agricultural projects. Instead of using the long and sometimes tedious method of polynomial long division, these theorems provide a quick and elegant way to find remainders and determine factors. Understanding these tools is fundamental to solving higher-degree polynomial equations, which are essential for modelling real-world situations, such as calculating the profit of a small business in Madina Market or designing a curved bridge support in Accra.
A. The Foundation: Polynomial Division
Before we learn the shortcuts, let's remember the basic principle of division. When you divide one polynomial, the *dividend* `P(x)`, by another, the *divisor* `D(x)`, you get a *quotient* `Q(x)` and a *remainder* `R(x)`.
This can be written as: `P(x) = D(x) × Q(x) + R(x)`
For example, if we divide `x³ + 2x² - 5x - 6` by `(x - 2)` using long division, we find that the quotient is `x² + 4x + 3` and the remainder is `0`. So, `x³ + 2x² - 5x - 6 = (x - 2)(x² + 4x + 3) + 0`.