Find the center and radius of the circle x2 + y2 - 16x = 0

y = √ - x2 + 16x or y = - √ - x2 + 16x

The answer is (8)

Move all variables to the left side and all constants to the right side. x2 + y2 - 16x=0

Complete the square for x2 - 16x

(x-8) 2 - 64

Substitute (x-8) 2 - 64 for x2 - 16x in the equation

x2 + y2 - 16x=0 x2 + y2 - 16x=0 - (x-8) 2-64+y2=0

Move - 64 to the right side of the equation by adding 64 to both sides.

(x-8) 2 + y2 = 0+64

Add 0 and 64 to get 64.

(x-8) 2 + y2 = 64

This is the form of a circle. Use this form to determine the center and radius of the circle.

(x-h) 2 + (y-k) 2 = r2

Match the values in this circle to those of the standard form. The variable r represents the radius of the circle, h represents the x-offset from the origin, and k represents the y-offset from origin.

r=8 h=8 k=0

The center of the circle is found at (h, k). Center: (8,0)

These values represent the important values for graphing and analyzing a circle. Center: (8,0) Radius: 8