Question

Equation of a circle whose centre is origin and radius is equal to the distance between the lines $x=1$and $x=-1$ is

Answer 1

Distance between lines $x=1$ and $x=-1$

$r-2$ units

centre , $0\equiv (h,k)\equiv (0,0)$

Equation : $(x-h{)}^2+(y-k{)}^2=r^2$

$(x-0{)}^2+(y-0{)}^2=2^2$

$\therefore x^2+y^2=4$