Consider the following statements in respect of a skew-symmetric matrix A of order 3:
1. All diagonal elements are zero.
2. The sum of all the diagonal elements of the matrix is zero.
3. is orthogonal matrix.
Which of the statements given above are correct?

If  p > 0 and  q < 0, then:

The rank of the matrix $$\begin{bmatrix}-1 & 2 & 5 \\2 & -4 & a - 4 \\1 & -2 & a + 1\end{bmatrix}\text{ is:} \\[12pt]$$​​

The solution set of $$|3 - 4x| \geq 9$$​ is:

The matrix which describes the rotation of x and y-axis through an angle θ about the origin is given by :

If P'(x', y') is the reflection of the point P(x, y) on the x-axis, then the matrix which describe the reflection of point P(x, y), in the x-axis is :

The matrix which describes the reflection of a point P(x, y) through the origin is:

If  $$n×n$$ matrix A has only one non-zero element, rank of  A is

The sum of the eigenvalues of the matrix $$\begin{pmatrix} 5 & 4 \\1 & 2\end{pmatrix}$$ is​

If $$A = \begin{pmatrix} \alpha & 0 \\1 & 1\end{pmatrix}, \quad B = \begin{pmatrix} 1 & 0 \\5 & 1\end{pmatrix}$$and $$A^2=B$$, then value of $$\alpha$$ is​

If $$I$$ be the $$2×2$$ identity matrix and $$A = \begin{pmatrix} 2 & -1 \\-1 & 2\end{pmatrix}$$, then $$A^2$$ is equal to​