Question

write the formal for equation of circle whose centre is (h,k) and radies is r​

Answer 1

Answer:Here your answer

Step by step:

Equation of a Circle

A circle is the set of all points in a plane at a given distance (called the radius ) from a given point (called the center.)

Circle showing radius and diameter

A line segment connecting two points on the circle and going through the center is called a diameter of the circle.

Assume that (x,y) are the coordinates of a point on the circle shown. The center is at (h,k) , and the radius is r .

Circle showing radius and diameter

Use the Distance Formula to find the equation of the circle.

(x2−x1)2+(y2−y1)2−−−−−−−−−−−−−−−−−−√=d

Substitute (x1,y1)=(h,k),(x2,y2)=(x,y) and d=r .

(x−h)2+(y−k)2−−−−−−−−−−−−−−−√=r

Square each side.

(x−h)2+(y−k)2=r2

The equation of a circle with center (h,k) and radius r units is (x−h)2+(y−k)2=r2 .