Jawapan:
# "vertex =" (1.5,1.75) #
# "fokus =" (1.5,2) #
# "directrix: y = 1.5 #
Penjelasan:
# y = a (x-h) ^ 2 + k "bentuk puncak parabola" #
# "vertex =" (h, k) #
# "fokus =" (h, k + 1 / (4a)) #
# y = x ^ 2-3x + 4 "persamaan parabola anda" #
# y = x ^ 2-3xcolor (merah) (+ 9 / 4-9 / 4) + 4 #
# y = (x-3/2) ^ 2-9 / 4 + 4 #
# y = (x-3/2) ^ 2 + 7/4 #
# "puncak" = (h, k) = (3 / 2,7 / 4) #
# "vertex =" (1.5,1.75) #
# "fokus =" (h, k + 1 / (4a)) #
# "fokus =" (1.5,7 / 4 + 1 / (4 * 1)) = (1.5,8 / 4) #
# "fokus =" (1.5,2) #
# "Dapatkan directrix:" #
# "ambil titik (x, y) pada parabola" #
# "mari" x = 0 #
# y = 0 ^ 2-3 * 0 + 4 #
# y = 4 #
# C = (0,4) #
# "mencari jarak untuk fokus" #
# 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 #
