在直线l:x+3y=0上有一点P,它到原点的距离等于它到直线l':3x+y+2=0的距离,（1)试求点P的坐标;

(1)x + 3y = 0,x = -3yP(-3p,p)OP = √[(-3p)² + p²] = √10|p|到直线l':3x+y+2=0的距离h = |-9p + p + 2|/√10 = |8p - 2|/√10√10|p| = |8p - 2|/√105|p| = |4p - 1|5p= ±(4p- 1)p = -1,P(3,-1)或p =...