Final answer:
The derivative of the constant function f(x) = 7 is 0 because the slope of the tangent line to a constant function is always horizontal, indicating no change.
Step-by-step explanation:
When considering the function f(x) = 7, which is a constant function, the slope of the tangent line at any point on the graph is horizontal. In mathematics, the slope of a horizontal line is 0, because there is no change in the y-value as the x-value changes. Therefore, the derivative of a constant function is 0.