Найдем производные данных функций и вычислим их значения в точке \( x_0 = \frac{\pi}{4} \).
1. \( y = 2 \cos x \)
Производная: \( y' = -2 \sin x \).
При \( x_0 = \frac{\pi}{4} \): \( y' = -2 \sin \frac{\pi}{4} = -2 \cdot \frac{\sqrt{2}}{2} = -\sqrt{2} \).
2. \( y = -\sqrt{2} \cos x \)
Производная: \( y' = -\sqrt{2} \cdot (-\sin x) = \sqrt{2} \sin x \).
При \( x_0 = \frac{\pi}{4} \): \( y' = \sqrt{2} \sin \frac{\pi}{4} = \sqrt{2} \cdot \frac{\sqrt{2}}{2} = 1 \).
3. \( y = 2 \sin x \)
Производная: \( y' = 2 \cos x \).
При \( x_0 = \frac{\pi}{4} \): \( y' = 2 \cos \frac{\pi}{4} = 2 \cdot \frac{\sqrt{2}}{2} = \sqrt{2} \).
4. \( y = \mathrm{ctg} x \)
Производная: \( y' = -\frac{1}{\sin^2 x} \).
При \( x_0 = \frac{\pi}{4} \): \( y' = -\frac{1}{\sin^2 \frac{\pi}{4}} = -\frac{1}{(\frac{\sqrt{2}}{2})^2} = -\frac{1}{\frac{2}{4}} = -\frac{1}{\frac{1}{2}} = -2 \).
5. \( y = -\sqrt{2} \sin x \)
Производная: \( y' = -\sqrt{2} \cos x \).
При \( x_0 = \frac{\pi}{4} \): \( y' = -\sqrt{2} \cos \frac{\pi}{4} = -\sqrt{2} \cdot \frac{\sqrt{2}}{2} = -1 \).
| Функция | Значение производной при \( x_0 = \frac{\pi}{4} \) |
| \( y = 2 \cos x \) | 4: -2 |
| \( y = -\sqrt{2} \cos x \) | 2: 1 |
| \( y = 2 \sin x \) | 5: \(\sqrt{2}\) |
| \( y = \mathrm{ctg} x \) | 1: -2 |
| \( y = -\sqrt{2} \sin x \) | 3: -1 |
Ответ: 1 - 4, 2 - 2, 3 - 5, 4 - 1, 5 - 3.