x² + y² = 81.
x² + y² = 4.
x2 + y2 = 81
x2 + y2 = r2, where r is the radius.
It is x2 + y2 = 4
The equation of circle is (x−h)^2+(y−k)^2 = r^2, where h,k is the center of circle and r is the radius of circle. so, according to question center is origin and radius is 10, therefore, equation of circle is x^2 + y^2 = 100
x2 + y2 = 64
x² + y² = 81.
x² + y² = 4.
x2 + y2 = 81
x2 + y2 = r2, where r is the radius.
It is x2 + y2 = 4
That's the equation of a circle with its center at the origin and a radius of 8.
Centre = (0,0), the origin; radius = 11
A unit circle is a circle of radius 1. If it's center is at the origin of an xy-coordinate system, then the equation is x (squared) + y (squared) = 1
(x - 0)2 + (y - 0)2 = 49
It is the equation of a circle with radius of 6 and its center at the origin.