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Ex 4.4, 18 (MCQ) - Chapter 4 Class 12 Determinants
Last updated at April 16, 2024 by Teachoo
Chapter 4 Class 12 Determinants
Concept wise
- Finding determinant of a 2x2 matrix
- 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
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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 4.4, 18 If A is an invertible matrix of order 2, then det(A−1) is equal to A. det (A) B. 1/(det (A)) C. 1 D. 0 We know that AA-1 = I Taking determinant both sides |"AA−1" |= |I| |A| |A-1| = |I| |A| |A-1| = 1 |A-1| = 1/(|A|) Since |A| ≠ 0 Hence, |A-1| = 1/(|A|) is valid Thus, the correct answer is B
