Question

已知直線l:x-y-1=0,l₁:2x-y-2=0,若直線l₂與l₁關(guān)于l對稱,則l₂的方程是(    )

A.x-2y+1=0                    B.x-2y-1=0

C.x+y-1=0                     D.x+2y-1=0

Answer 1

思路解析:首先可求出兩條直線的交點(diǎn)為(1,0),然后任取l₁上一點(diǎn)(2,2),求出其關(guān)于直線x-y-1=0的對稱點(diǎn)為(3,1),之后利用兩點(diǎn)式求出l₂的方程為x-2y-1=0.

答案:B