As shown in Figure 11, parabola and straight line y = kx-4k (k)

As shown in Figure 11, parabola and straight line y = kx-4k (k)

(1) straight line y = KX - 4K = K (x - 4) a (4,0), B (0, - 4K) C (- 10,0), axis of symmetry x = (- 10 + 4) / 2 = - 3Y = a (x + 10) (x - 4) x = 0, y = - 40A = - 4K, k = 10atan ∠ dbo = 3 / 4 = do / ob = 3 / (- 4K) K