Question

The equation of the circle in the first quadrant which touches each axis at a distance 5 from the origin is

• A. $x^2+y^2+5x+5y+25=0$
• B. $x^2+y^2-10x-10y+25=0$
• C. $x^2+y^2-5x-5y+25=0$
• D. $x^2+y^2+10x+10y+25=0$

Answer 1

The correct option is B

$x^2+y^2-10x-10y+25=0$

The centre of the circle which touches each axis in first quadrant at a distance 5, will be (5, 5) and radius will be 5.
$\therefore (x-h{)}^2+(y-k{)}^2=a^2\Rightarrow (x-5{)}^2+(y-5{)}^2=(5{)}^2$
$\Rightarrow x^2+y^2-10x-10y+25=0.$