Question

Which of the following equations correctly represents a circle centered at the

Answer 1

Answer: $x^2+y^2=7^2$ (C)

Step-by-step explanation:

Alright, lets get started.

The standard equation of a circle is given by :

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

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

As per given question, center should be origin, it means the center should be $(h,k)=(0,0)$

As per given question, radius should be 7, it means $r=7$

Plugging the value of (h,k) and r in standard equation of circle,

$(x-0)^2+(y-0)^2=7^2$

$x^2+y^2=7^2$ ...... Answer (C)

Hope it will help :)