Question

y＝ x－1与抛物线y＝－ x 2交于A,B两点,与y轴交于点C以AB为直径的圆与直线x＝m有公共点,求m的取值范围

Answer 1

y=x-1

y=-x^2

x-1=-x^2

x1=(-1+√5)/2 x2==(-1-√5)/2

A点坐标[(-1+√5)/2,(-3+√5)/2]

B点坐标[(-1-√5)/2,(-3-√5)/2]

圆心坐标(-1/2,-3/2),半径=√5/2

m=-1/2±√5/2