Doubtify – JEE Ki Taiyaari, Simple Bhasha Mein

  ❓ Concept 🎬 Adj(A) & Determinant Tricks Adjugate (adj) questions look scary in JEE — but in reality, sab kuch power rules pe based hota hai . Agar 4 identities yaad hain, toh 10 seconds mein answer . 1️⃣ What is adj(A)? Adjugate of a matrix A A A : adj ( A ) = transpose of cofactor matrix \text{adj}(A) = \text{transpose of cofactor matrix} ⭐ Most Important Identity: A ⋅ adj ( A ) = adj ( A ) ⋅ A = ∣ A ∣   I A \cdot \text{adj}(A) = \text{adj}(A) \cdot A = |A|\,I 📌 Ye identity almost har JEE matrix question ka base hoti hai. 2️⃣ adj(A) for Invertible A If: ∣ A ∣ ≠ 0 |A| \ne 0 Then: adj ( A ) = ∣ A ∣   A − 1 \text{adj}(A) = |A|\,A^{-1} 👉 Matlab adj(A) behaves like det(A) × inverse . 3️⃣ Determinant of adj(A) — BIG TRICK 🔥 For any n × n n \times n  matrix: ∣ adj ( A ) ∣ = ∣ A ∣   n − 1 |\text{adj}(A)| = |A|^{\,n-1} 📌 Very powerful rule : adj lene se determinant power mein convert ho jaata hai For JEE (most common): n = 3 n =...