函数题求解!!急

来源：百度知道 编辑：UC知道 时间：2024/06/16 11:00:30
Find the equation of the line through the point (4, 7) that cuts off the least area from the first quadrant. Give your answer using the form below.
y - A = B(x - C)
A =
B =
C =

y - 7 = B(x - 4) 即y=Bx+7-4B
由于直线与xy轴的交点分别为((4B-7)/B，0),(0，7-4B)
所形成的区域面积为S=|(4B-7)/B||7-4B|=
(7-4B)^2/|B|
S=(7-4B)^2/|B|=16|B|+49/|B|-D(D为与B无关量)
取最小值的条件16|B|=49/|B|
所以|B|=7/4
由图知B=-7/4
A=4,B=-7/4,C=7

y - 7 = B(x - 4)
y = Bx + (7- 4B)

y-intercept at: (0, 5 - 4B)
x-intercept at: ((-7 + 4B)/B, 0)

你们怎么都用英语了啊