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![Ex 4.1, 6 - Find determinant |A| if A = [1 1 -2 2 1 -3 5 4 -9] - Ex 4.1](https://cdn.teachoo.com/8a8a97e5-3d8a-418c-aad1-353ec377cd93/slide14.jpg)
Ex 4.1, 6 - Chapter 4 Class 12 Determinants
Last updated at August 17, 2026 by Teachoo
Evalute determinant of a 3x3 matrix
Chapter 4 Class 12 Determinants
Concept wise
- Finding determinant of a 2x2 matrix
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Evalute determinant of a 3x3 matrix
- Area of triangle
- Equation of line using determinant
- Finding Minors and cofactors
- Evaluating determinant using minor and co-factor
- Find adjoint of a matrix
- Finding Inverse of a matrix
- Inverse of two matrices and verifying properties
- Finding inverse when Equation of matrice given
- Checking consistency of equations
- Find solution of equations- Equations given
- Find solution of equations- Statement given
- Verifying properties of a determinant
- Two rows or columns same
- Whole row/column zero
- Whole row/column one
- Making whole row/column one and simplifying
- Proving Determinant 1 = Determinant 2
- Solving by simplifying det.
- Using Property 5 (Determinant as sum of two or more determinants)
Transcript
Ex 4.1, 6 If A = [■8(1&1&−2@2&1&−3@5&4&−9)], find |A| |A| = |■8(1&1&−2@2&1&−3@5&4&−9)| = 1 |■8(1&−3@4&−9)| – 1 |■8(2&−3@5&−9)| + (–2) |■8(2&1@5&4)| = 1 (1(–9) – 4(–3)) – 1 (2( –9) – 5(–3)) –2(2(4) – 5(1)) = 1 (−9 + 12) + 1 (−18 + 15) – 2 (8 – 5) = 1(3) − 1 (−3) – 2 (3) = 3 + 3 – 6 = 6 – 6 = 0 Hence, |A|= 0
