Докажи тождества 1) {\sin 47\degree + \sin 61\degree-\sin 11\degree\,\mathrlap{\,\!-}}{-\sin 25\degree = \cos 7\degree}; 2) {\cos 24\degree + \cos 48\degree\,\mathrlap{\,\!-}}{-\cos 84\degree \cos 12\degree =\dfrac{1}{2}}.

Задание

Докажи тождества

\({\sin 47\degree + \sin 61\degree-\sin 11\degree\,\mathrlap{\,\!-}}\) \({-\sin 25\degree = \cos 7\degree}\) ;
\({\cos 24\degree + \cos 48\degree\,\mathrlap{\,\!-}}\) \({-\cos 84\degree \cos 12\degree =\dfrac{1}{2}}\) .