KCET2012MathematicsStraight Lines
The reflection of the point (1,1) along the line y=-x is
Options
- A(0,0)
- B(-1,1)
- C(-1,-1)
- D(1,-1)
Correct answer
C. (-1,-1)
Step-by-step solution
The mid-point of P Q lies on x+y=0 gathered ( h +1 2 )+ ( k +1 2 )=0 ~h + k =-2 gathered Again, PQ is perpendicular to AB . aligned & & ( k -1 ~h -1 )(-1) &=-1 & & ( m ₁ ~m ₂=-1 ) & & k -1 &= h -1 k &= h aligned Put k = h in Eq. (i), we get 2 ~h =-2 h =1 k =-1