The y-intercept of a graph of the function is the y-coordinate of the point where the graph intersects y-axis. The x-coordinate of this point is 0. Therefore, to find the y-intercept, plug in x = 0 into the given equation:
`y_i = y(0) = 0^2 - 4*0 - 4`
The y-intercept is -4. The point where the graph intersects y-axis is (0, -4).
You can also see the above result on the graph below: