grafik 2x*=9x+12 dantitik puncak utk y ya ya?

jawab

y = 2x² - 9x - 12
x = -b/2a = -(-9)/2(2)
x = 9/4

y = 2(9/4)² - 9(9/4) - 12
y = - 22 ¹/₈