圆薯弯M:(x-a)^2+(y-b)^2=r^2
y=0,(x-a)^2=r^2-b^2,x1+x2=2a
x=0,(y-b)^2=r^2-a^2,y1+y2=2b
圆M在两坐数梁闷标轴上的渣升四个截距之和为2:
2a+2b=2
a+b=1......(1)
圆M经过点A(4,2),B(-1,3)两点:
(4-a)^2+(2-b)^2=r^2......(2)
(-1-a)^2+(3-b)^2=r^2......(3)
(2)-(3):
10-10a+2b=0
5a-b=5......(4)
(1)+(4):
6a=6
a=1,b=0,r^2=13
圆的方程:(x-1)^2+y^2=13