№ 19.1 Геометрія = № 38.1 Математика
Дано △ABC, ∠C = 90°. Знайдіть:
1. sin A;
2. cos B;
3. tg A;
4. cos A;
5. sin B;
6. tg B.
Розв'язок:
1. $sin\ \angle A\ =\ \frac{BC}{AB}\ =\ \frac{8}{10}\ =\ \frac{4}{5};$
2. $cos\ \angle B\ =\ \frac{BC}{AB}\ =\ \frac{8}{10}\ =\ \frac{4}{5};$
3. $tg\ \angle A\ =\ \frac{BC}{AC}\ =\ \frac{8}{6}\ =\ \frac{4}{3};$
4. $cos\ \angle A\ =\ \frac{BC}{AB}\ =\ \frac{6}{10}\ =\ \frac{3}{5};$
5. $sin\ \angle B\ =\ \frac{AC}{AB}\ =\ \frac{6}{10}\ =\ \frac{3}{5};$
6. $tg\ \angle B\ =\ \frac{AC}{BC}\ =\ \frac{6}{8}\ =\ \frac{3}{4}.$