Đề thi, bài tập trắc nghiệm online Đại số tuyến tínhĐề 3 – Bài tập, đề thi trắc nghiệm online Đại số tuyến tính Đăng vào 2 Tháng 5, 2026 bởi admin Đề 3 – Bài tập, đề thi trắc nghiệm online Đại số tuyến tính Đề 3 – Bài tập, đề thi trắc nghiệm online Đại số tuyến tính Số câu30Quiz ID14818 Làm bài Câu 1 1. For a square matrix A, if λ is an eigenvalue, what is always true about A - λI? A A. A - λI is invertible. B B. A - λI is the zero matrix. C C. The determinant of (A - λI) is zero. D D. The rank of (A - λI) is equal to the dimension of A. Câu 2 2. What does the Gram-Schmidt process achieve? A A. Diagonalizes a matrix. B B. Finds eigenvalues and eigenvectors. C C. Transforms a basis into an orthonormal basis. D D. Solves systems of linear equations. Câu 3 3. Which of the following is a property of eigenvalues of a real symmetric matrix? A A. Eigenvalues must be complex numbers. B B. Eigenvalues must be positive integers. C C. Eigenvalues must be real numbers. D D. Eigenvalues must be zero. Câu 4 4. Which of the following is NOT a subspace of R²? A A. The set of all vectors of the form (x, 0). B B. The set of all vectors of the form (x, x). C C. The set of all vectors of the form (x, 1). D D. The set of all vectors of the form (0, y). Câu 5 5. Consider a linear transformation T: R² → R². If T rotates every vector by 90 degrees counterclockwise, what is the matrix representation of T? A A. [[0, 1], [1, 0]] B B. [[0, -1], [1, 0]] C C. [[1, 0], [0, 1]] D D. [[-1, 0], [0, -1]] Câu 6 6. If A is an n x n matrix and c is a scalar, how does det(cA) relate to det(A)? A A. det(cA) = c * det(A) B B. det(cA) = cⁿ * det(A) C C. det(cA) = det(A) + c D D. det(cA) = det(A)ᶜ Câu 7 7. What is a linear transformation? A A. A function that maps vectors to scalars. B B. A function between two vector spaces that preserves vector addition and scalar multiplication. C C. Any function between vector spaces. D D. A function that maps scalars to vectors. Câu 8 8. What is the dimension of the vector space of all m x n matrices? A A. m + n B B. m - n C C. m * n D D. max(m, n) Câu 9 9. If A and B are n x n matrices, which of the following is generally NOT true? A A. det(AB) = det(A)det(B) B B. det(A + B) = det(A) + det(B) C C. det(Aᵀ) = det(A) D D. det(kA) = kⁿdet(A) where k is a scalar Câu 10 10. For a system of linear equations Ax = b to have at least one solution, what must be true about the ranks of the augmented matrix [A|b] and the coefficient matrix A? A A. rank(A) must be less than rank([A|b]). B B. rank(A) must be greater than rank([A|b]). C C. rank(A) must be equal to rank([A|b]). D D. There is no condition on the ranks for a solution to exist. Câu 11 11. If a square matrix A is invertible, what is the inverse of its transpose, (Aᵀ)⁻¹? A A. (A⁻¹)ᵀ B B. -(A⁻¹)ᵀ C C. Aᵀ D D. -Aᵀ Câu 12 12. Which of the following is a condition for a square matrix to be invertible? A A. Its determinant is zero. B B. Its rank is less than its dimension. C C. Its null space contains only the zero vector. D D. It has linearly dependent columns. Câu 13 13. Which of the following is NOT a property of vector spaces? A A. Closure under vector addition. B B. Closure under scalar multiplication. C C. Commutativity of scalar multiplication (c(dv) = (cd)v). D D. Closure under matrix multiplication. Câu 14 14. Which of the following sets of vectors in R³ is linearly independent? A A. {(1, 0, 0), (2, 0, 0), (0, 1, 0)} B B. {(1, 1, 0), (0, 1, 1), (1, 2, 1)} C C. {(1, 0, 1), (0, 1, 0), (0, 0, 1), (1, 1, 1)} D D. {(1, 2, 3), (0, 1, 2), (0, 0, 1)} Câu 15 15. What is the dot product of two vectors also known as? A A. Cross product. B B. Scalar product. C C. Vector product. D D. Matrix product. Câu 16 16. Given two vectors u = (1, 2) and v = (3, k). For what value of k are vectors u and v orthogonal? A A. 6 B B. -6 C C. 3/2 D D. -3/2 Câu 17 17. Given a matrix A, under what condition is A = A⁻¹? A A. When A is the identity matrix. B B. When A is the zero matrix. C C. When A² = I (where I is the identity matrix). D D. When A is a diagonal matrix. Câu 18 18. If matrix A is a square matrix and its determinant is zero, which of the following statements is always true? A A. The matrix A is invertible. B B. The matrix A has full rank. C C. The system of linear equations Ax = 0 has only the trivial solution. D D. The system of linear equations Ax = 0 has infinitely many solutions. Câu 19 19. Which of the following is true about the column space of a matrix A? A A. It is always equal to the row space of A. B B. It is a subspace of the column space of Aᵀ. C C. It is the set of all possible linear combinations of the columns of A. D D. It is always orthogonal to the null space of A. Câu 20 20. Which of the following operations is NOT always valid for matrix multiplication? A A. Associativity: (AB)C = A(BC) B B. Distributivity over addition: A(B + C) = AB + AC C C. Commutativity: AB = BA D D. Scalar multiplication: c(AB) = (cA)B = A(cB) Câu 21 21. What is the determinant of a matrix if two of its rows are identical? A A. Equal to 1. B B. Equal to -1. C C. Equal to 0. D D. Equal to the product of the diagonal elements. Câu 22 22. What is the rank of a matrix? A A. The number of rows in the matrix. B B. The number of columns in the matrix. C C. The dimension of the null space of the matrix. D D. The dimension of the column space (or row space) of the matrix. Câu 23 23. Which of the following describes an eigenvector of a matrix A? A A. A vector that is transformed into the zero vector when multiplied by A. B B. A vector that, when multiplied by A, only changes in magnitude, not direction. C C. A vector that is orthogonal to all columns of A. D D. A vector that is a linear combination of the rows of A. Câu 24 24. Which of the following is NOT a basic operation when solving a system of linear equations using Gaussian elimination? A A. Swapping two rows. B B. Multiplying a row by a non-zero scalar. C C. Adding a multiple of one row to another row. D D. Multiplying two rows together. Câu 25 25. What is the characteristic polynomial of a square matrix A used to find? A A. Eigenvectors. B B. Eigenvalues. C C. Determinant. D D. Trace. Câu 26 26. What is the cofactor of an element aᵢⱼ in a matrix A? A A. The determinant of the matrix obtained by deleting the i-th row and j-th column. B B. The negative of the determinant of the matrix obtained by deleting the i-th row and j-th column. C C. (-1)ⁱ⁺ʲ times the determinant of the matrix obtained by deleting the i-th row and j-th column. D D. The element aⱼᵢ. Câu 27 27. What is the determinant of an elementary matrix resulting from swapping two rows of the identity matrix? A A. 1 B B. -1 C C. 0 D D. 2 Câu 28 28. What is the null space of a matrix A? A A. The set of all vectors b such that Ax = b has a solution. B B. The set of all vectors x such that Ax = 0. C C. The set of all linear combinations of the columns of A. D D. The set of all linear combinations of the rows of A. Câu 29 29. If matrix A is diagonalizable, it means that A is similar to which type of matrix? A A. An upper triangular matrix. B B. A lower triangular matrix. C C. A diagonal matrix. D D. An identity matrix. Câu 30 30. What is the trace of a square matrix? A A. The determinant of the matrix. B B. The sum of all elements in the matrix. C C. The sum of the diagonal elements of the matrix. D D. The product of the diagonal elements of the matrix. Đề 2 – Bài tập, đề thi trắc nghiệm online Sinh học di truyền Đề 4 – Bài tập, đề thi trắc nghiệm online Công nghệ chế tạo máy