x^2+y^2-2x=0(x-1)²+y²=1O(1,0)r=13x+4y+m=0d=|3+m|/51)相交d|3+m|/5<1|3+m|<5-5-82)相切|3+m|/5=1m=-8 m=23)相离|3+m|/5>1m<-8 m>2
