Antwoord:
vertex: (2,5, -15,75)
symmetrie-as: x = 2.5
Uitleg:
#f (x) = 3x ^ 2-15x + 3 #
#f (x) = 3 x ^ 2-5x + 3 #
#f (x) = 3 (x-5/2) ^ 2-25 / 4 + 3 #
#f (x) = 3 (x-5/2) ^ 2-75 / 4 + 3 #
#f (x) = 3 (x-5/2) ^ 2-15 3/4 #
#-X 5/2 = 0 #
# X = 5/2 #
#f (x) = 3 (0) ^ 2 -15 3/4 #
#f (x) = - 15 3/4 #
# daarom voor hoekpunt: (5/2, -15 3/4) #
# daarom "symmetrie-as": x = 5/2 #