Grade 11 & 12 Mathematics: How to Prove the Cosine Rule | iCampSA

Struggling to master your trigonometry derivations for the exams? In this video, we break down the step-by-step mathematical proof for the Cosine Rule, specifically tailored for Grade 11 and Grade 12 National Senior Certificate (NSC) and IEB learners. We walk through the geometric constructions and algebraic steps using Pythagoras' theorem to prove why: b² = a² + c² - 2ac cos(B) We cover both mandatory exam variations : • Case 1: The Acute-Angled Triangle Proof 📐 • Case 2: The Obtuse-Angled Triangle Proof 📐 Make sure you know these geometric constructions inside out, as they are a frequent source of high-value marks in your Mathematics Paper 2! What we cover: Introduction to the Cosine Rule Construction & Proof: Acute-Angled Triangle Construction & Proof: Obtuse-Angled Triangle Summary & Key Exam Tactics WANT HIGHER MARKS IN MATHS & SCIENCE? Get top-tier academic support with iCampSA! We offer expert, curriculum-aligned tutoring designed to make complex concepts simple. Join our daily support groups where dedicated tutors answer your questions throughout the day. Visit our website to sign up: https://icampsa.co.za/ Contact us: [email protected] If this walkthrough made the geometry clear, please give it a LIKE, drop a comment with any questions, and SUBSCRIBE to the channel for more matric masterclasses! #Grade11Maths #MatricMaths #Trigonometry #CosineRule #iCampSA #MathsMadeFun #CAPS #Matric2026 #ExamPrep #Paper2Maths #icampsa