How do you find the equation of the circle given Center at the origin; r=squareroot 5?
The standard form of the equation of a circle is.
where (a ,b) are the coordinates of the centre and r, the radius.
here the centre is at the origin, hence a = 0 , b = 0
substitute into the standard equation.
#(x-0)^2+(y-0)^2=(sqrt5)^2" simplifying to"#
#x^2+y^2=5" the equation of the circle"#
However, it is worth noting and remembering that when the circle is centred at the origin, the standard equation reduces to.