Предмет: Алгебра, автор: klja2000

Знайдіть кут А трикутника АВС, если АВ=1 ВС=2 АС=√3

Ответы

Автор ответа: Аноним

2² = (√3)² + 1² - 2·√3·1 ·Cos A
4 = 3 +1 - 2√3Cos A
2√3Cos A = 0
Cos A = 0
угол А = 90

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