如圖11,抛物線和直線y=kx-4k(k

如圖11,抛物線和直線y=kx-4k(k

沒見有圖,所以按敘述做.如不一致,請發圖.(1)直線y = kx - 4k = k(x - 4)A(4,0),B(0,-4k)C(-10,0),對稱軸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…