Final answer:
The value of f(-5) for the function f(x) = -(1/2)x² + 4 is -8.5, after substituting x with -5 and simplifying the expression.
Step-by-step explanation:
To find the value of f(-5), we need to understand the function definition provided, but it seems that there is a typo in the function notation given in the question. Assuming a typical quadratic function of the form f(x) = -(1/2)x² + 4, which would be a parabola opening downwards with the vertex at (0, 4), we can substitute x with -5 to determine f(-5).
f(-5) = -(1/2)(-5)² + 4
f(-5) = -(1/2)(25) + 4
f(-5) = -12.5 + 4
f(-5) = -8.5
Therefore, the value of f(-5) is -8.5.