Which is the standard equation for a circle centered at the origin with radius r? A. x2 + y2 = r B. x2 = y2 + r2 C. x + y = r D. x2 + y2 = r2

Question

asked Jul 8, 2019 160k views

2 Answers

Mintuz · Answer 1 · 2019-07-12T04:50:06+0000

The standard equation of a circle is given by :

(x-h)^(2) + (y-k)^(2) =r^(2)

where (h,k) is the center and r is the radius of circle.

Now in the question we are given that the center is at origin.

So coordinate of center becomes (h,k) =(0,0)

radius is r.

So plugging these values in the standard equation, we get,

(x-0)^(2) + (y-0)^(2) =r^(2)

Simplifying,

(x)^(2) + (y)^(2) =r^(2)

Answer is option first:

x² + y² =r²