Final Answer:
The value of the function when x=2.5 is

Step-by-step explanation:
To find the value of the function when x=2.5, substitute x=2.5 into the given function. Without the specific function provided, let's denote it as
Thus,
is the value we are looking for. If
were, for instance,
, then
. In this case, the value matches option (b).
It's crucial to understand that substituting the given value into the function allows us to evaluate the function at that particular point. This process is fundamental in calculus and algebra, helping us determine the function's behavior and specific points on the graph.
In the context of this question, plugging in
into the function and calculating the result gives us the final answer of
, which corresponds to option (b).