Question

Giúp em bài 614 với ạ, từ câu 4 ấy ạ

Answer 1

12: \(=\dfrac{1}{2}\cdot2\cdot sin\left(\dfrac{pi}{48}\right)\cdot cos\left(\dfrac{pi}{48}\right)\cdot cos\left(\dfrac{pi}{24}\right)\cdot cos\left(\dfrac{pi}{12}\right)\cdot cos\left(\dfrac{pi}{6}\right)\)

\(=\dfrac{1}{2}\cdot sin\left(\dfrac{pi}{24}\right)\cdot\cos\left(\dfrac{pi}{24}\right)\cdot\cos\left(\dfrac{pi}{12}\right)\cdot\cos\left(\dfrac{pi}{6}\right)\)

\(=\dfrac{1}{4}\cdot sin\left(\dfrac{pi}{12}\right)\cdot cos\left(\dfrac{pi}{12}\right)\cdot cos\left(\dfrac{pi}{6}\right)\)

\(=\dfrac{1}{8}\cdot sin\left(\dfrac{pi}{6}\right)\cdot cos\left(\dfrac{pi}{6}\right)\)

=1/16*sin pi/3=1/32*căn 3