設原來直線上一點(a,b)關于M的對稱點為(x,y)則x+a=4 y+b=6所以a=4-x,b=6-y4(4-x)+(6-y)-1=0
16-4x+6-y-1=0
4x+y-21=0x+a???=4????y+b???=6??4(4-x)+(6-y)-1=0=4a+b-1=0?ɡ?4a+b-1???????????????????????M(2.3)??????????????????????????????????????????????X.Y??? 4x+y-1=0???????????????????????????2????????????????? ???2??????????? ???????????d=|a*A+b*B+C|/???(A^2+B^2)?4x2+1x3-1?/??(4²+1²)=?4x2+1x3+c?/??(4²+1²)10=?11+c?c=-1??21 C=-1????????C=21 ???????ɡ??????????????`|4????2`+`1??`??3-1|???-1?????????????c=2??????????????????лл??4x+y-1=0 Ax+By+C=0c=-1C=21?? ???????11+c=??10|4????2+1????3-1|???????-1????????????-1???Ax??By??C??0 ??P??Xo??Yo?????????????????????????AXo??BYo??C???????A²??B²??l1??l2??P??l1??l2??????????????-1?????l1?????C1????????????l2??????C2???-1??l1??c1??4x+y-1=0 Ax+By+C=0A=4B=1 C=-1 =??=