Show that ` |[sinalpha, cosalpha, cos(alpha+delta)],[sinbeta, cosbeta, cos(beta+delta)],[singamma, cosgamma, cos(gamma+delta)]|=0 `

Explanation

To show that

\[
\begin{vmatrix}
\sin \alpha & \cos \alpha & \cos(\alpha + \delta) \\
\sin \beta & \cos \beta & \cos(\beta + \delta) \\
\sin \gamma & \cos \gamma & \cos(\gamma + \delta)
\end{vmatrix} = 0,
...