Svar:
# "Vertex" (- 6/7823/49) #
Forklaring:
# Y = (x-3) ^ 2-4x ^ 2-x + 4 #
# "1-take derivat af funktionen med hensyn til x" #
# (d y) / (d x) = 2 (x-3) * 1-8x-1 #
# "1-equalize with zero and solve for x" #
# 2 (x-3) -8x-1 = 0 #
# 2x-6-8x-1 = 0 #
# -6x-7 = 0 #
# -6x = 7 #
# X = -6/7 #
# "skriv x = -6 / 7 i den oprindelige ligning og beregne for y" #
#Y = (- 6 / 7-3) ^ 2-4 (-6/7) ^ 2 - (- 6/7) + 4 #
#Y = (- 27/7) ^ 2-4 (36/49) + 6/7 + 4 #
# Y = 729 / 49-144 / 49 + 34/7 #
# Y = 585/49 + 34/7 #
# Y = 585/49 + 238/49 #
# Y = 823/49 #
# Y = 16,8 #
