Question

The co-ordinates of the image of the origin $O$ with respect to the straight line $x+y+1=0$ are :

• A. $(-\frac{1}{2},-\frac{1}{2})$
• B. $(-2,-2)$
• C. $(1,1)$
• D. $(-1,-1)$

Answer 1

The correct option is D $(-1,-1)$

Let $(h,k)$ be the image of $(0,0)$ w.r.t. $x+y+1=0$

$\frac{h-0}{1}=\frac{k-0}{1}=-2(\frac{1}{2})$
$h=k=-1$
Hence, the image is $(-1,-1)$