Question

Which equation represents a circle. need an steps and explanation

Answer 1

Equation of circle : ( x - h) ^2 + ( y - k^2) = r^2

Where h and k are the coordinates of center.

So, h = 0, k = - 8 and r = 8

( x - 0)^2 + ( y - ( - 8))^2 = 8^2

x^2 + ( y + 8) ^2 = 64

Last option is the correct one.

Answer 2

Given:

Radius of circle is 8 and centre of circle is (0,-8)

To Find:

Equation of circle?

Step-by-step explanation:

• we know equation of circle is given by the formula

           $(x-h)^2+(y-k)^2=r^2$

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

         we have r=8 and (h,k)=(0,-8) put these value in above equation

            $(x-0)^2+(y+8)^2=64\\\Rightarrow x^2+(y+8)^2=64$

Thus option d is right answer.