Cho hai vectơ u,v có ∣u∣=3,∣v∣=4 và góc giữa hai vectơ u,v bằng 60∘. Tích vô hướng u.v bằng
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Trong đó: $|\overrightarrow{u}|=3$, $|\overrightarrow{v}|=4$ và $(\overrightarrow{u},\overrightarrow{v})=60^\circ$.
Suy ra: $\overrightarrow{u}.\overrightarrow{v} = 3.4.cos(60^\circ) = 12.\dfrac{1}{2} = 6$.
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Taking Home the World Cup
Standing just 36 centimeters tall, the FIFA World Cup Trophy symbolizes the pinnacle of football achievement. Every four years, teams worldwide compete for it, but no one ever takes the trophy home. Made of 18-carat gold, the original trophy remains under FIFA's protection, with winners receiving only a replica. This measure safeguards it from theft, as the trophy has been stolen twice in its history.
The original trophy was made by a French sculptor, Abel LaFleur, and was called the “Jules Rimet Cup,” in honor of the founder of the World Cup tournament. Sometime during the first three World Cup events (1930, 1934, and 1938), the name changed to simply the “World Cup.” Then during World War II, not much was seen or heard of the trophy. It was being kept hidden in a shoe box under the bed of Dr. Ottorino Barassi, the Italian vice-president of FIFA, to prevent it from falling into the hands of the Nazi army. In 1966, the Cup was stolen during a public showing of the trophy prior to the World Cup tournament in England. Luckily, it was found a short time later, none the worse for wear, in a trash container by a little dog named Pickles. Four years later, Brazil earned permanent possession of the original trophy by winning its third World Cup title. Unfortunately, the trophy was stolen a second time in 1983 and was never recovered. The Brazilian Football Association had to have a duplicate trophy made.
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Our passionate (2)_________ need your generous support to continue their vital mission abroad.
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Tính chất nào sau đây không phải của tốc độ của một chuyển động?
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Cuộc kháng chiến chống Pháp (1945 – 1954) của nhân dân Việt Nam diễn ra trong bối cảnh nào sau đây?
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là
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