Let two matrices be A=[1, −2;−4, 1],B=[0, 5;3, 8] What is A + B?
- [1, 7;7, 9]
- [1, 7;−1, 9]
- [1, −7;−7, −7]
- [1, 3;−1, 9]
Let x=[2; 7; 4; 1] What is 3 * x?
- [6, 21, 12, 3]
- [2/3, 7/3, 4/3, 1/3]
- [6; 21; 12; 3]
- [2/3; 7/3; 4/3; 1/3]
Let u be a 3-dimensional vector, where specifically u=[2; 1; 8]. What is transpose(u)?
- [2, 1, 8]
- [8; 1; 2]
- [2; 1; 8]
- [8, 1, 2]
Let u and v be 3-dimensional vectors, where specifically u=[3; −5; 4] and v=[1; 2; 5] What is transpose(u)*v?
13
Let A and B be 3x3 (square) matrices. Which of the following must necessarily hold true? Check all that apply.
- A * B = B * A
- If C = A * B, then C is a 3x3 matrix.
- If B is the 3x3 identity matrix, then A * B = B * A
- A * B * A = B * A * B