Question

Will give Medal!

Which of the following is the equation of a circle whose center is at the origin and whose radius is 4?

x(squared)+ y(squared) = 2

x(squared) + y(squared) = 4

x(squared) + y(squared) = 16

Answer 1

THE GENERAL EQUATION OF A CIRCLE IS \[(x-a)^{2}+(y-b)^{2}=r ^{2}\]

(a,b) is the coordinate of the centre and r is the radius

since a and b is zero when centre lies at origini, it means that all the circles mentioned have centre at origin

for radius to be 4, r^2=16

x^2+y^2=16 is the answer