Final answer:
The value of the function f(x) at x = -1 is found by substituting x = -1 into the function's equation, resulting in f(-1) = 5.
Step-by-step explanation:
The question requires us to find the value of the function f(x) at x = -1. Based on the provided piecewise function definition f(x) = -x + 4 for x = -13, we can calculate the value for x = -1 as follows:
f(-1) = -(-1) + 4
f(-1) = 1 + 4
f(-1) = 5
Therefore, the value of the function f(x) at x = -1 is 5.