Q121.A pair of values of α and β for which the matrix A = 1 2 0 2 1 3 6 α β is invertible, is
Correct answer: α = 1, β = 5
Q122.For matrices A = 1 4 -2 1 7 -6 0 -k k, B = k -2k -10 -k k 4 -k k 3, k ≠ 0 Which of the following is true?
Correct answer: A = –kB–1
Q123.The value of the determinant 1 1 1 1 α β γ δ β + γ + δ + α +β δ α β γ is
Correct answer: 0
Q124.If A = 3 1 7 5, the value of x and y, such that A2 = yA – xI, are respectively
Correct answer: 8, 8
Q125.A is a square matrix such that A2 = I, then (A– I)3 +(A + I)3 – 7A:
Correct answer: A
Q126.The diagonal elements of a skew-symmetric matrix are
Correct answer: 0
Q127.In a matrix A = ij 3×3 a, if 11 12 13 a = 2,a = 5,a = –2 and A11 = 5, A12 = 4, A13 = 4, then determinant A is
Correct answer: 22
EnglishDSSSB 23 SEP 2018 (9 AM-11 AM)
Q128.Which of the given statements is true?
Correct answer: If A is a diagonalizable matrix, then AT is diagonalizable.
EnglishDSSSB 23 SEP 2018 (9 AM-11 AM)
Q129.Consider the subset: S= {[3,1,–1], [2,2,–1], [–5,–2,2], [1,3,1]} of 3. If A is the matrix having columns as vectors of set S, then: S= {[3,1,–1], [2,2,–1], [–5,–2,2], [1,3,1]} of 3.
Correct answer: the set S is linearly dependent and the matrix A has rank 3.
EnglishDSSSB 23 SEP 2018 (9 AM-11 AM)
Q130.Let A be nonsingular diagonalizable matrix of order 3 with eigenvalues λ1, λ2, λ3. Then A-1 diagonalizable if.
Correct answer: 1 2 3 2, 1, 3 λ = λ = λ =
Q131.The value of the determinant 43 1 6 35 7 4 17 3 2 is
Correct answer: 0
Q132.The characteristic roots of the matrix 5 4 A 1 2 = are
Correct answer: 1, 6
Q133.For square matrices A and B, which of the following is true?
Correct answer: (A+B)' = A'+B'
Q134.The characteristic roots of a Hermitian matrix are
Correct answer: real
Q135.Every square matrix can be expressed as
Correct answer: sum of symmetric and skew-symmetric matrices
Q136.Every diagonal element of a skew-symmetric matrix is
Correct answer: zero
Q137.The eigen values of the matrix a h g A 0 b 0 0 c c = are
Correct answer: a, b, c
Q138.A square matrix P satisfies P2 = I – P. If Pn = 5I – 8P, then n is equal to
Correct answer: 6
Q139.If A is a 3× × ×3 non-singular matirx, then det (adj A) is equal to
Correct answer: (det A)2
Q140.If ((()) 2 1 x x f x x x 1 x 1 x = then the value of (((()))) 3 f 3 is
Correct answer: –4