Решение:
- a) 2 sin(3x - \(\frac{\pi}{4}\)) = \(\sqrt{3}\)
\( \sin(3x - \frac{\pi}{4}) = \frac{\sqrt{3}}{2} \)
\( 3x - \frac{\pi}{4} = \frac{\pi}{3} + 2\pi n \) или \( 3x - \frac{\pi}{4} = \\[ \pi - \frac{\pi}{3} \] + 2\pi n \), где \( n \in \mathbb{Z} \).
\( 3x = \frac{\pi}{4} + \frac{\pi}{3} + 2\pi n = \frac{7\pi}{12} + 2\pi n \) \( \Rightarrow \) \( x = \frac{7\pi}{36} + \frac{2\pi n}{3} \).
\( 3x = \frac{\pi}{4} + \frac{2\pi}{3} + 2\pi n = \frac{11\pi}{12} + 2\pi n \) \( \Rightarrow \) \( x = \frac{11\pi}{36} + \frac{2\pi n}{3} \), где \( n \in \mathbb{Z} \). - б) 4 (x²-1) = 16(x+1)
\( 4(x-1)(x+1) = 16(x+1) \)
\( 4(x-1)(x+1) - 16(x+1) = 0 \)
\( (x+1)[4(x-1) - 16] = 0 \)
\( (x+1)(4x - 4 - 16) = 0 \)
\( (x+1)(4x - 20) = 0 \)
\( 4(x+1)(x-5) = 0 \)
\( x = -1 \) или \( x = 5 \). - в) log5²(x) - 5 log5(x) + 6 = 0
Пусть \( y = \log_5(x) \). Тогда уравнение примет вид: \( y^2 - 5y + 6 = 0 \).
\( (y-2)(y-3) = 0 \)
\( y = 2 \) или \( y = 3 \).
\( \log_5(x) = 2 \) \( \Rightarrow \) \( x = 5^2 = 25 \).
\( \log_5(x) = 3 \) \( \Rightarrow \) \( x = 5^3 = 125 \).
(Учтено, что \( x > 0 \) для логарифма).
Ответ: a) \( x = \frac{7\pi}{36} + \frac{2\pi n}{3}, x = \frac{11\pi}{36} + \frac{2\pi n}{3}, n \in \mathbb{Z} \); б) \( x = -1, x = 5 \); в) \( x = 25, x = 125 \).