嫣然枫少
幼苗
共回答了36个问题采纳率:83.3% 举报
(1)
顶点M(1,0),二次函数可表达为y = a(x - 1)²
过A(3,4):a(3 - 1)² = 4,a = 1
二次函数:y = (x - 1)² = x² - 2x + 1
A(3,4)在直线y = x + m上:3 + m = 4,m = 1
直线:y = x + 1
(2)
y = x + 1 = x² - 2x + 1
x² - 3x = x(x - 3) = 0,x = 0 (x = 3,点A)
B(0,1)
B关于x轴的对称点为B'(0,-1)
AB'的方程:(y + 1)/(4 + 1) = (x - 0)/(3 - 0)
取y = 0,x = 3/5
Q(3/5,0)
(∆OBQ与∆OB'Q全等,BQ = B'Q,B',Q,A在一条直线上)
1年前
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