Question

Find the equation of the circle with center at the origin and radius 4

Answer 1

Equation of a circle with center ( h , k ) and radius r is
${(x - h)}^{2} + ( {y - k)}^{2} = {r}^{2}$
Equation of a circle with center at the Origin i.e, (0,0) and radius r = 4
$( {x - 0)}^{2} + ( {y - 0)}^{2} = {4}^{2} \\ {x}^{2} + {y}^{2} = 16$