Demand and supply are the two core ideas that explain how markets work — from why your favourite phone gets cheaper over time to why grocery prices jump after a bad harvest. In this short guide you'll discover the law of demand and the law of supply, how prices reach a market equilibrium, and what causes shifts in curves instead of simple movements along them. By the end you'll be able to read a demand-and-supply diagram, explain real-world examples, and connect these ideas to IB DP Economics concepts like price elasticity and market responses.

• What you'll learn: basic definitions, key determinants, equilibrium and price formation, and simple examples (smartphones, seasonal crops, and tax effects)
• Why it matters: helps explain everyday price changes, policy effects (taxes, subsidies, price controls), and prepares you for IB exam-style questions

Ready to see how a few lines on a graph predict real-world prices? Let's break it down step-by-step.

Whether you're preparing for IB DP exams or building a strong math foundation, this focused trigonometry study guide covers the six core ratios — sin, cos, tan, csc, sec, cot — and shows how to use them in proofs, graphs, and real problems. Inside you'll find:

• Quick formula sheet: definitions, reciprocal relationships, Pythagorean and co-function identities.
• Visual tools: unit circle, right-triangle diagrams, and graphs of sin, cos, tan and their reciprocals.
• Problem types & tips: solving trig equations, inverse functions, triangle solving (SAS/ASA/ASA), and IB exam strategies.
• Applications & extensions: wave motion, circular motion, vectors, and links to calculus for HL students.

Clear worked examples, exam-style practice questions, and memory-check tips help you move from memorising to understanding — step by step.

Travel from 1800 to 1848 and uncover the dramatic political, economic, and social transformations that shaped early 19th-century America. This unit covers the Louisiana Purchase, the War of 1812, the Market Revolution, the Second Great Awakening, rising reform movements, Jacksonian democracy, and the growing sectional tensions over slavery. Perfect for AP US History students, this guide gives clear themes, exam-focused tips, and study strategies so you can connect facts to the big-picture arguments graders look for.

What you'll get:

• Core themes & timeline to memorize efficiently
• Source-based study tips for DBQs and Short Answers
• Real-world connections that show why Unit 4 still matters today

Unlock the core ideas of Environmental Science for IB DP Year 12 with a clear, exam-ready summary that connects theory, data skills, and real-world problems. In this concise guide you'll get:

• Key systems: ecosystems, energy flow, and nutrient cycles
• Human dimensions: population dynamics, consumption patterns, pollution, and climate change
• Solutions & ethics: sustainability, conservation, environmental economics, and ethical decision-making

Each point links to practical IB skills — experimental design, data analysis and evaluation, and fieldwork — so you can see how concepts appear in assessments and how they apply to real-life problems like resource management and climate policy.

Cleaning your bottom properly is a basic life skill that keeps you healthy, comfortable, and confident — especially during long school days, sports, or after using the restroom. This friendly, age-appropriate guide gives clear, practical steps you can follow, explains common tools (toilet paper, water, bidets), and shares tips to prevent irritation and stay fresh. No judgement — just useful facts and easy habits.

• What you'll learn: step-by-step routine, best tools to use, how to avoid irritation, and good handwashing and bathroom etiquette
• Why it matters: prevents infections, reduces discomfort, and helps you feel confident in social and school settings

APUSH Unit 4 covers the dramatic transformation of the early American republic (circa 1800–1848) — a time of political change, economic growth, and powerful reform movements. This guide gives you a clear roadmap to the people, events, and themes you need for class and the AP exam. Expect to learn about the Jeffersonian vision, the War of 1812 and Era of Good Feelings, the Market Revolution, Jacksonian democracy, westward expansion, and the major social reform movements that reshaped American life.

• Quick wins: focus on cause-and-effect chains (e.g., Market Revolution → urban growth → reform movements).
• Exam tip: practice DBQ/LEQ prompts that ask about continuity/change and national vs. sectional priorities.
• Why it matters: these developments shaped modern American politics, economic systems, and social activism — and you’ll spot their echoes in today’s debates.

Ready for targeted review, memorable stories, and AP-style practice? Let’s make Unit 4 click in your brain so you can write sharp, evidence-rich essays under pressure.