Final answer:
The relationship between arousal and performance according to the Yerkes-Dodson law is described by an inverted U-shaped function where performance improves with arousal to an optimal point, after which it declines with too much arousal.
Step-by-step explanation:
According to the Yerkes-Dodson law, the relationship between arousal and performance can be described by a(n) inverted U-shaped function. This means that more arousal leads to better performance, but only up to a point; beyond that point, too much arousal can actually hinder performance. The law also states that the optimal arousal level depends on the complexity and difficulty of the task at hand, with simple tasks being performed best under higher arousal levels and complex tasks requiring lower levels of arousal for optimal performance.