Question

A circle has the equation `x^2+y^2=16`. How do you find the center ,radius and the intercepts?

Answer 1

centre (0,0) , r=4 , (±4,0), (0,±4)

Explanation:

The standard form of the equation of a circle is

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

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

`x^2 + y^2 = 16 " is in this form "`

with a = b = 0 and r = 4

hence this circle has centre at the origin (0,0) and radius 4

The intercepts will therefore be (± 4,0) and (0, ± 4 )