Докажи тождество: 1) {4\cos \left(\dfrac{\pi}{3}-x\right)\cos \left(\dfrac{\pi}{3}+x\right)\mathrlap{\,=}} {=4\cos^2 x-3}; 2) {4\sin \left(\dfrac{\pi}{3}-x\right)\sin \left(\dfrac{\pi}{3}+x\right)\mathrlap{\,=}} {=3-4\sin^2 x}.

Задание

Выполни задание

Докажи тождество:

\({4\cos \left(\dfrac{\pi}{3}-x\right)\cos \left(\dfrac{\pi}{3}+x\right)\mathrlap{\,=}}\) \({=4\cos^2 x-3}\) ;
\({4\sin \left(\dfrac{\pi}{3}-x\right)\sin \left(\dfrac{\pi}{3}+x\right)\mathrlap{\,=}}\) \({=3-4\sin^2 x}\) .