Antwoord:
# "Vertex =" (1.5,1.75) #
# "Focus =" (1.5,2) #
# "directrix: y = 1,5 #
Uitleg:
# y = a (x-h) ^ 2 + k "de vertexvorm van parabool" #
# "Vertex =" (h, k) #
# "Scherpstelling =" (h, k + 1 / (4a)) #
# y = x ^ 2-3x + 4 "uw paraboolvergelijking" #
# Y = x ^ 2-3xcolor (rood) (+ 9 / 4-9 / 4) + 4 #
# Y = (x-3/2) ^ 2-9 / 4 + 4 #
# Y = (x-3/2) ^ 2 + 7/4 #
# "Top" = (h, k) = (3 / 2,7 / 4) #
# "Vertex =" (1.5,1.75) #
# "Scherpstelling =" (h, k + 1 / (4a)) #
# "Scherpstelling =" (1.5,7 / 4 + 1 / (4 * 1)) = (1.5,8 / 4) #
# "Focus =" (1.5,2) #
# "Find director:" #
# "neem een punt (x, y) op parabool" #
# "laten" x = 0 #
# Y = 0 ^ 2-3 * 0 + 4 #
# Y = 4 #
# C = (0,4) #
# "vind afstand tot focus" #
# J = sqrt ((1,5-0) ^ 2 + (2-4) ^ 2) #
# J = sqrt (2,25 + 4) #
# J = sqrt (6,25) #
# J = 2,5 #
# Directrix = 4-2,5 = 1,5 #
# Y = 1,5 #
