gambarkanlah grafik fungsi f(x) = x^2-7x-18 please bantuin...

memotong sumbu x ---> y = f(x) = 0
x² - 7x - 18 = 0
(x - 9)(x + 2) = 0
x = 9 dan x = -2
(-2,0)(9,0)
memotong sumbu y ---> x = 0
y = 0² - 7(0) - 18 = -18
(0,-18)
titik balik
2x - 7 = 0
x = 7/2
y = (7/2)² - 7(7/2) - 18 = -121/4