二次函数y=mx^2+（m-3）x-3(m＞0)
x1+x2=(3-m)/m.(x1+x2)^2=(9-6m+m^2)/m^2
x1*x2=-3/m
AB=x2-x1=4
(x2-x1)^2=(x1+x2)^2-4x1*x2=(9-6m+m^2)/m^2+12/m=16
9-6m+m^2+12m=16m^2
15m^2-6m-9=0
5m^2-2m-3=0
(5m+3)(m-1)=0
m1=1.y=x^2-2x-3=(x+1)(x-3)
m2=-3/5.y=-3x^2/5-18x/5-3=-3/5*(x^2+6x+5)=-3/5*(x-1)(x-5)
C(0,-3)
A1(-1,0)
B1(3,0)
A2(1,0)
B2(5,0)
圆M1圆心(1,-1),半径√5
圆M2圆心(3,7/3),半径√85/3
面积自己求吧