(a) They completed the table of values as shown x -2.0 -1.5 -1.0 0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 y 11 0 -9 -16 -21 -24 -25 -24 -21 -16 -9 0 11 (b)(i) The graph (b)(ii)(\(\alpha\), deduce that 4x\(^2\) - 8x - 21 = 3 - 21 so that y = -18. From the graph, the point of intersection of y = -18 and y = 4x\(^2\) - 8x - 21 was atx = {-0.35 \(\pm\) 0.1, 2.3 \(\pm\) 0.1} (b)(ii)(\(\beta\)), the equation 4x\(^2\) - 8x - 21 = 0 which can be written as 4x\(^2\) - x - 7x - 21 = -x. This implies that 4x\(^2\) - 8x - 21 = -x. But, y = 4x\(^2\) - 8x - 21 so that y = -x, Next was to draw the line y = -x and from the graph, the point of intersection with the curve y = 4x\(^2\) - 8x - 21 was at x = {3.3 \(\pm\) 0.1, -1.6 \(\pm\) 0.1}