Решение
y = arccos(log₃sin8x)² * (cosx/sin²3x)
y` = [ arccos(log₃sin8x)²]` * (cosx/sin²3x) + arccos(log₃sin8x)² * [(cosx/sin²3x)]` =
= {1 / √(log₃sin8x)² * [2*(log₃sin8x)²] * [1/(sin8x * ln3)] * 8cosx} * (cosx/sin²3x) +
+ arccos(log₃sin8x)² * [(sinx * sin²3x - cosx * 2sin3x * cos3x * 3) / sin⁴3x]]