Answer: y + (-4) = 0 or y - 4 = 0
Reasoning:
Data:
Slope, m = 0
Point C (0,4)
Solution:
Slope 0 means the the line is horizontal, i.e. parallel to the x-axis. The equation of such line is a constant: y = constant.
Given that the point C(0,4) is in the line, the constant is 4, and the equation is:
y = 4, which in standard form is y + (-4) = 0.
That means, that the value of the function does not depends on the value of x or, what is the same, that for any value of x the value of the function is 4.