The rate of change for your linear function is the slope. You can use the points C and D to calculate it. slope = (y2 - y1)/(x2 - x1) = (-11 - (-1))/(2 - 0) = -10/2 = -5 I'm not sure what is meant by initial value, but maybe you are looking for the y-intercept of the line.
The y-intercept is the point where the line crosses the y axis, so where x = 0. You have that because your line passes through the point (0, -1). When x = 0, y = -1.
