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

• A. $x^2+y^2=1$
• B. $x^2+y^2=\sqrt{2}$
• C. $x^2+y^2=4$
• D. $x^2+y^2=-4$

Answer 1

The correct option is C $x^2+y^2=4$

Radius = 2, C (0, 0)

Equation of circle can be found from this, Which will be $x^2+y^2=4$