Question

The circumcentre of a triangle formed by the line $xy + 2x + 2y + 4 = 0$ and $x + y + 2 = 0$ is.

• A. (–1, –1)
• B. (0, –1)
• C. (1, 1)
• D. (–1, 0)

Answer 1

Answer: (A)

(–1, –1)

Answer 2

$x y + 2 x + 2 y + 4 = 0$ .....(i)

And $x + y + 2 = 0$ ......(ii)

from (i) and (ii), $x y = 0 \Rightarrow x = y = 0$

∴ Vertices of triangle are $( - 2,0 ) ( 0,0 ) ( 0 , - 2 )$

(In a right angled triangle circumcentre is mid point of hypotenuse)

∴ $( - 1 , - 1 )$ is the circumcircle.