The Circle

A circle is the locus

A circle is the locus of all points in a plane equidistant from a fixed point. The fixed point is the centre, the distance from the centre to any poin

The standard equation is (x

The standard equation is (x-h)^2+(y-k)^2=r^2, where (h,k) is the centre and r is the radius. For a circle with centre at the origin, the equation beco

The general equation is x^2+y^2+2gx+2fy+c=0

The general equation is x^2+y^2+2gx+2fy+c=0. It represents a circle with centre (-g,-f) and radius sqrt(g^2+f^2-c). The coefficients of x^2 and y^2 mu

If the end

If the end-points of a diameter are (x1,y1) and (x2,y2), then the circle is given by (x-x1)(x-x2)+(y-y1)(y-y2)=0. The result comes from the fact that

A circle with centre (h

A circle with centre (h,k) and radius r can be written as x=h+r cosθ and y=k+r sinθ, where 0≤θ<2π. As θ varies from 0 to 2π, the point traces the whol