Question

Which of the following is a row vector?

(a) \(\left[ \begin{array}{c c r } 0 & 1 & 2 \end{array}\right]\)

(b) \(\left[ \begin{array}{c c r r}  0\\   1  \\  2\end{array}\right]\)

(c) \(\left[ \begin{array}{c  r}  0 & 1\\ 1 &  2\end{array}\right]\)

(d) \(\left[ \begin{array}{c c r r} 0 & 3 & 6 \\  1 & 8 & 4  \\  0 & 5 & 7\end{array}\right]\)

This question was posed to me in an internship interview.

The query is from Matrix Algebra topic in section Matrix Algebra and Gaussian Elimination of Finite Element Method

Answer 1

The correct option is (a) \(\left[ \begin{array}{c c r } 0 & 1 & 2 \end{array}\right]\)

Best explanation: A matrix of (1 x n) dimension is called row vector. A matrix of (n x1) dimension is called column vector.

 For example

d=[ 1 2 3 4] is a row vector.

c = \(\left[ \begin{array}{c c r r}  0\\   1  \\  2\end{array}\right]\) is a column vector.