a positif = terbuka ke atas dan mempunyai nilai minimum
Baca Juga: Soal UTS PTS IPS Kelas 8 SMP MTs Disertai Kunci Jawaban dan Pembahasan
17. b
x = -b/2a
x = -(-4)/2.1
x = 4/2
x = 2
18. b
x = -b/2a
-3 = -6/2.a
-6a = -6
a = 1
y = 1.x^2 + 6x + (1-1)
y = x^2 +6x + 0
Nilai optimum
D/-4a
= (b^2 - 4ac)/-4a
= (6^2 - 4.1 . 0)/-4.1
= 36/-4
= -9