Предмет: Математика, автор: karinakarishka1

cos(n/7)cos(2n/7)cos(3n/7)

Ответы

Автор ответа: sedinalana

[sinπ/7*cosπ/7*cos2π/7*cos3π/7]/sinπ/7=[sin2π/7*cos2π/7*cos3π/7]/2sinπ/7=
=[sin4π/7*cos3π/7]/4sinπ/7=[sin(π-3π/7)*cos3π/7)/4sinπ/7=
=[sin3π/7*cos3π/7]/4sinπ/7=(sin6π/7)/8sinπ/7=[sin(π-π/7)]/8sinπ/7=
=(sinπ/7)/8sinπ/7=1/8

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The Louvre Museum
The Louvre Museum is one of the biggest museums in the world. The museum is in Paris, France and every year a lot of people visit it. The Museum has seven departments: Oriental and Islamic Antiquities; Egyptian Antiquities; Greek, Roman and Etruscan Antiquities; Sculptures; Paintings; Objects of Art; and Arts and Civilisations of Africa, Asia, Oceania and the Americas. The entrance fee is €7.50 from 9:00 am to 3:00 pm and €5.00 after 3:00 pm. The Louvre Museum is a fantastic place where you can see works of art from all over the world.

The Hermitage Museum
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The Metropolitan Museum of Art
The Metropolitan Museum is a beautiful museum in the city of New York. The museum has a lot of different departments including: American Decorative Arts; Asian arts; Drawings and Paintings; European Paintings; European Sculpture and Decorative Arts; Islamic Arts; and Modern Arts. The entrance fee is usually $12.00, but for students it's $7.00. The Metropolitan Museum is a place you have to visit when you are in the city of New York.

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