Nilai minimum fungsi f(x) = x kuadrat -2x + 9 adalah...

jawab
f(x) = x² -2x + 9
a = 1
b = -2
c = 9

nilai min= D/-4a
y = (b² -4ac)/(-4a)
y = ((-2)² -4(1)(9)) / (-4(1))
y = -32/-4
y = 8