Question

Вычисли: cos⁡ 47°30'*cos⁡17°30'+sin47°30' sin*17°30'

Answer 1

Ответ:

$\boxed{\cos 47^{\circ}30' \cdot \cos17^{\circ} 30' + \sin 47^{\circ}30' \cdot \sin17^{\circ} 30' = \dfrac{\sqrt{3} }{2} }$

Объяснение:

$\cos 47^{\circ}30' \cdot \cos17^{\circ} 30' + \sin 47^{\circ}30' \cdot \sin17^{\circ} 30' = \cos( 47^{\circ}30' - 17^{\circ} 30' ) =\cos 30^{\circ} =$

$=\dfrac{\sqrt{3} }{2}$