Question

求直线x-y-2=0以l:x+2y+1=0为对称轴的对称图形的方程

Answer 1

x-y-2=0.(1),k1=1

L:x+2y+1=0.(2),k(L)=-0.5

(2)-(1):y=-1,x=1

(k+0.5)/(1-0.5k)=(-0.5-1)/(1-0.5*1)

k=-7

y+1=-7*(x-1)

7x+y-6=0