Kunci Jawaban Matematika Kelas 9 Halaman 102, Tugas Latihan 2.3 Materi Sumbu Simetri dan Titik Optimum

Titik potong terhadap sumbu y (x = 0):

y = 2(0)² + 9(0)

y = 0

= (0, 0)

Titik puncak:

D = b² – 4ac = 9² – 4(2)(0) = 81

x = -b/2a = -9/2(2) = -9/4

y = -D/4a = -81/4(2) = -81/8

(-9/4 , -81/8)

b. y = 8x² – 16x + 6