Types of Matrices

Q.

Which among the following are triangular matrices?

1. $\left[\begin{array}{cc}1& 5\\ 0& 1\end{array}\right]$

2. $\left[\begin{array}{ccc}5& 0& 0\\ 1& 2& 0\\ 0& 3& 3\end{array}\right]$

3. $\left[\begin{array}{ccc}1& 3& 0\\ 2& 1& 3\\ 0& 2& 1\end{array}\right]$

4. $\left[\begin{array}{ccc}2& 3& 9\\ 1& 5& 0\\ 6& 0& 0\end{array}\right]$

Q. Null matrix will have all the elements as zero.

1. False
2. True

Q.

Define a matrix.

Q. An identity matrix is a diagonal matrix in which all of the diagonal elements are equal to .

1. \N
2. 1
3. 2