【高中英数】a circle through A(-2,5) and B(2,-1) ,and its centre lies on the straight line x-y+1=0.Find the equation of the ci
问题描述：
【高中英数】a circle through A(-2,5) and B(2,-1) ,and its centre lies on the straight line x-y+1=0.Find the equation of the circle.
答
一个圆经过点A（-2,5）和B（2,-1）,圆心在直线x-y+1=0上.求圆方程.线段AB的斜率是(-1-5)/(2+2)=-3/2AB的中点是(0,2)所以AB中垂线的方程是y=2x/3+2圆心在AB中垂线上,与x-y+1=0联立解出圆心坐标O(3,4)OA²=(3+2)...修改了一下，应该是平方抱歉我没看明白那个AB中垂线那里中垂线与AB垂直，所以斜率与AB是负倒数且经过AB中点，用点斜式就算出来了那个y=2x/3+2是什麽意思？除以 3 然後+2 ？我懂了！谢谢你客气