Question

How do you find the radius and center of a circle with the equation `( x - 1) ^2 + (y - 3) ^2 =16`?

Answer 1

radius = 4 , centre = (1,3)

Explanation:

The standard form of the equation of a circle is :

`(x - a )^2 + (y - b )^2 = r^2`

where (a , b ) are the coordinates of centre and r , the radius

the equation `(x - 1 )^2 + (y - 3 )^2 = 16 " is in this form "`

and by comparison , centre = (1 , 3) and r = 4