Resposta:
# "vèrtex =" (1,5,1,75) #
# "focus =" (1,5,2) #
# "directrix: y = 1,5 #
Explicació:
# y = a (x-h) ^ 2 + k "la forma de vèrtex de la paràbola" #
# "vertex =" (h, k) #
# "focus =" (h, k + 1 / (4a)) #
# y = x ^ 2-3x + 4 "la vostra equació paràbola" #
# y = x ^ 2-3xcolor (vermell) (+ 9 / 4-9 / 4) + 4 #
# y = (x-3/2) ^ 2-9 / 4 + 4 #
# y = (x-3/2) ^ 2 + 7/4 #
# "vèrtex" = (h, k) = (3 / 2,7 / 4) #
# "vèrtex =" (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) #
# "Cerca directriu:" #
# "agafa un punt (x, y) a la paràbola" #
# "deixa" x = 0
# y = 0 ^ 2-3 * 0 + 4 #
# y = 4 #
# C = (0,4) #
# "trobar la distància per enfocar" #
# 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 #
