A(4, 0), OA = 2AB, B(4, 2), D(2, 1)
k =2*1 = 2
n = k/4 = 1/2
F(1, 2)
OF的斜率为2,折痕斜率为-1/2
OF中点I(1/2, 1)
解析式:y -1 =(-1/2)(x - 1/2)
y = -x/2 5/4
A(4, 0), OA = 2AB, B(4, 2), D(2, 1)
k =2*1 = 2
n = k/4 = 1/2
F(1, 2)
OF的斜率为2,折痕斜率为-1/2
OF中点I(1/2, 1)
解析式:y -1 =(-1/2)(x - 1/2)
y = -x/2 5/4