4th Roots of Unity Form an Abelian Group | Proof | BCS405A

In today’s class, I solved a very important question from Module 5 – Group Theory in Discrete Mathematical Structures (BCS405A): 📘 Question: “Show that the 4th roots of unity form an Abelian group.” W4 = { 1 , −1 , i , −i } 📚 What you’ll learn in this video: ✔ What are roots of unity ✔ Understanding the set W4 = { 1 , −1 , i , −i } ✔ How to verify group properties step by step:  • Closure  • Associativity  • Identity element  • Inverse element ✔ How to check commutative property ✔ Why the group is Abelian ✔ Writing the proof properly for exams ✔ Common mistakes students make This type of question is frequently asked in exams and is very important for understanding Group Theory concepts and proofs. 🎯 Perfect for: Engineering students studying BCS405A Students preparing for semester exams Learners practicing group theory proofs 💡 “Check all properties — that’s how you prove a group.” 👉 Like 👍, Comment 💬, Share 📲, and Subscribe 🔔 for more clear and exam-focused Discrete Mathematics tutorials. 🔖 Hashtags #GroupTheory #AbelianGroup #RootsOfUnity #DiscreteMathematics #Algebra #MathProof #EngineeringStudents #ExamPreparation #MathsTutorial #bcs405a