Final answer:
Without the explicit definition of the function f, we cannot compute f(121) or f(-31). For a function represented as a horizontal line, it has a constant value within its domain. To find P(0 < x < 12) for a probability function, we would need to integrate the function over that range, which isn't possible without the formula.
Step-by-step explanation:
The student's question asks for the value of the function f at specific points, f(121) and f(-31). However, without the explicit definition of the function f, it is impossible to calculate these values. Usually, a function will have a formula, such as f(x) = x^2 or f(x) = 2x + 3, which allows us to input a value for x and find the corresponding output. Since the question doesn't provide this crucial information, we cannot give a definitive answer.
For the second function mentioned, f(x) being a horizontal line, the value of the function will be the same for any x within the given domain, assuming the function's output is the constant value of the line. Therefore, f(x) is constant for 0 ≤ x ≤ 20.
In probability, given a continuous probability function restricted between two values, the probability P(0 < x < 12) would typically be calculated by integrating the function over that range. However, since we don't have the function's formula, we cannot compute the probability.