Q64 / 180 · KCET 2008 · Mathematics
The equation of the smallest circle passing through the points $(2,2)$ and $(3,3)$ is
- A$x^{2}+y^{2}+5 x+5 y+12=0$
- Correct answerB$x^{2}+y^{2}-5 x-5 y+12=0$
- C$x^{2}+y^{2}+5 x-5 y+12=0$
- D$x^{2}+y^{2}-5 x+5 y-12=0$
Solution
Let the points be $A=(2,2)$ and $B=(3,3)$. Since, the circle passing through these points, so they satisfie the equation of the circle.
Now, taking option (b),
Let $\mathrm{S} \equiv \mathrm{x}^{2}+\mathrm{y}^{2}-5 \mathrm{x}-5 \mathrm{y}+12=0$
At $\mathrm{A}=(2,2)$
$2^{2}+2^{2}-5(2)-5(2)+12=0$
$\Rightarrow$
$0=0$
At $\mathrm{B}=(3,3)$
$3^{2}+3^{2}-5(3)-5(3)+12=0$
$\Rightarrow$
$0=0$
Hence, option (b) is correct.
Hence, the correct answer is option: 'B'.