Question

The equation of circle with centre $(1,2)$ and tangent $x+y-5=0$ is

(a) $x^2+y^2+2 x-4 y+6=0$

(b) $x^2+y^2-2 x-4 y+3=0$

(c) $x^2+y^2-2 x+4 y+8=0$

(d) $x^2+y^2-2 x-4 y+8=0$

Answer 1

SOLUTION — Radius $=\frac{|1+2-5|}{\sqrt{1+1}}=\sqrt{2}$

$\therefore$ Equation of circle is $(x-1)^2+(y-2)^2=(\sqrt{2})^2$

$\Rightarrow \quad x^2+y^2-2 x-4 y+3=0$

So, The correct option of this question will be (B).