直线方程化为 x+y=1 ,因此斜率为-1 ,设倾斜角为 a ,则 a = 135°,cosa = -√2/2 ,sina = √2/2 ,直线的参数方程改写为x = 2-√2/2*t ,y = -1+√2/2*t ,代入圆的方程,得 (2-√2/2*t)^2+(-1+√2/2*t)^2=4 ,化简得 ...