Question

ma poate ajuta cineva va rog, stiu ca sunt usoare dar nu reusesc sa inteleg cum sa fac ​

Answer 1

Răspuns:

1/4

Explicație pas cu pas:

$\cos\Big(\dfrac{23\pi}{12}\Big)\cdot \sin\Big(\dfrac{\pi}{12}\Big) = \cos\Big(\dfrac{24\pi -\pi}{12}\Big)\cdot \sin\Big(\dfrac{\pi}{12}\Big) = \\ \\ = \cos\Big(2\pi - \dfrac{\pi}{12}\Big)\cdot \sin\Big(\dfrac{\pi}{12}\Big) = \cos\Big(\dfrac{\pi}{12}\Big) \cdot \sin\Big(\dfrac{\pi}{12}\Big) = \\ \\ = \dfrac{1}{2} \cdot 2\cdot \cos\Big(\dfrac{\pi}{12}\Big) \cdot \sin\Big(\dfrac{\pi}{12}\Big) = \\ \\ = \dfrac{\sin\Big(2\cdot \dfrac{\pi}{12}\Big)}{2} =\dfrac{\sin\Big(\dfrac{\pi}{6}\Big)}{2}= \dfrac{1}{4}$