Răspuns:
# "Vertex =" (1.5,1.75) #
# "Focus =" (1.5,2) #
# "directrix: y = 1,5 #
Explicaţie:
# y = a (x-h) ^ 2 + k "forma vertex a parabolei" #
# "Vertex =" (h, k) #
# "Focus =" (h, k + 1 / (4a)) #
# y = x ^ 2-3x + 4 "ecuația parabolei tale" #
# Y = x ^ 2-3xcolor (roșu) (+ 9 / 4-9 / 4) + 4 #
# Y = (x-3/2) ^ 2-9 / 4 + 4 #
# Y = (x-3/2) ^ 2 + 7/4 #
# "Vertex" = (h, k) = (3 / 2,7 / 4) #
# "Vertex =" (1.5,1.75) #
# "Focus =" (h, k + 1 / (4a)) #
# "Focus =" (1.5,7 / 4 + 1 / (4 * 1)) = (1.5,8 / 4) #
# "Focus =" (1.5,2) #
# "Gaseste directrix:" #
# "ia un punct (x, y) pe parabola" #
# "lasa" x = 0 #
# Y = ^ 2-3 * 0 0 + 4 #
# Y = 4 #
# C = (0,4) #
# "găsiți distanța pentru a focaliza" #
# J = sqrt ((1.5-0) ^ 2 + (2-4) ^ 2) #
# J = sqrt (2,25 + 4) #
# J = sqrt (6,25) #
# J = 2,5 #
# Directricea = 4-2.5 = 1,5 #
# Y = 1,5 #
