Consider the following Assertion [a] and Reason [r] [a] M is an orthogonal matrix, but not a skew-symmetric matrix. Determine the correctness or otherwise...

X and Y are two matrices such that XY and X+Y are both defined. The CORRECT statement from amongst the following is

If the determinant and trace of a 2×2 matrix M are -1 and 0 respectively, then the determinant of M+M⁻¹ is