Which of the following matrix has no inverse?
(a) \( \begin{pmatrix} -1&1\\1&-4 \end{pmatrix}\)
(b) \( \begin{pmatrix} 2&-1\\-4&2 \end{pmatrix}\)
(c) \( \begin{pmatrix} cos\,a&sin\,a\\-sin\,a&cos\,a \end{pmatrix}\)
(d) \( \begin{pmatrix} sin\,a&sin\,a\\-cos\,a&cos\,a \end{pmatrix}\)