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一、步步为营逐步消参u00182例1求与圆x2+y2-2x=0相外切,且与直线x+3y=0相切于点M(3,-3)的圆的方程.思路一:设所求圆的方程为:(x-a)2+(y-b)2=r2(a、b、r为参数).由题意可得:(a-1)2+b2=r+1,(a-3)2+(-3-b)2=r2,|a+3b|2=r.此方程组理论上可解,但解起来却非常烦琐,如果采用下列方法,“?
First, step by step to gradually eliminate the parameters of the u00182 Example 1 and the circle x2 + y2-2x = 0 out of phase, and with the straight line x + 3y = 0 tangent to the point M (3, -3) circle equation. : Let the equation for the circle be: (xa)2+(yb)2=r2 (a, b, and r are parameters). From the meaning of the question: (a-1)2+b2=r+1, ( A-3)2+(-3-b)2=r2,|a+3b|2=r. This system of equations is theoretically solvable, but the solution is very tedious. If you use the following method, "?