Day 15: Inequalities | Middle Stage Mathematics
Apex Institute of Maths and Sciences
Level 1: The Quest (Concept) ๐
In math, things aren’t always exactly equal. An Inequality tells us about the relationship between two values that are not equal. Itโs like a balance scale that is tipped to one side!
The Symbols of the Quest:
\( < \) : Less Than (The "L" shape)
\( > \) : Greater Than
\( \leq \) : Less than or equal to
\( \geq \) : Greater than or equal to
Think of the symbol as an alligator’s mouthโit always wants to eat the bigger number!
Level 2: Power-Ups (Tools/Methods) โก
- Use an Open Circle (\(\circ\)) for \( < \) or \( > \).
- Use a Closed Circle (\(\bullet\)) for \( \leq \) or \( \geq \).
- Draw an arrow to the Right for “Greater Than”.
- Draw an arrow to the Left for “Less Than”.
Solving Trick: Solving an inequality is just like solving an equation \( (x + 2 = 5) \), EXCEPT: If you multiply or divide by a Negative Number, you MUST flip the symbol!
Example: \( -2x < 10 \) becomes \( x > -5 \)
Level 3: Mini-Boss Battles (Daily Life) ๐ฎ
To ride the “Mega Coaster,” your height \(h\) must be at least 120 cm. This is written as: \( h \geq 120 \). If you are 119 cm, you can’t ride!
Your mobile data limit is 5GB. To avoid extra charges, your usage \(u\) must be less than or equal to 5. Equation: \( u \leq 5 \).
Level 4: Home Quests (Activities) ๐
Look at the weather forecast with your parents. Find the “Low” and “High” temperatures. Write an inequality for the temperature \(t\) today. (Example: \( 25 \leq t \leq 38 \)).
Find 5 items in your house that are shorter than 30 cm. List them and write the inequality \( \text{Length} < 30 \).
IT is so interesting