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3 votes
Find the center and radius of the circle x2 + y2 – 16x = 0

2 Answers

6 votes
y=x2+16x or y=x2+16x

User Djhoese
by
7.8k points
0 votes
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=8k=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
User Aaron Thomas
by
7.8k points