Y = kx+8, memotongkan y= x(pangkat 2 )-8x+12 (D<0)

kx + 8 = x^2 - 8x + 12
x^2 -8x - kx + 12 - 8 = 0
x^2 -(8+k)x + 4 = 0

jika persamaan kuadrat: ax^2 + bx + c = 0, maka
a = 1, b = -(8+k), c = 4

D < 0
b^2 - 4ac < 0
(8+k)^2 - 4(1)(4) < 0
64 + 16k + k^2 - 16 < 0
k^2 + 16k + 48 < 0
(k + 12)(k + 4) < 0

HP: { -12 < k < -4}