What are the standard form, radius, and center?

The equation of a circle is x^2+y^2-4x+2y-11=0.

2 Answers
May 21, 2018

r=4

Explanation:

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May 21, 2018

Standard form (x-2)^2+(y+1)^2=16
Radius is 4
Centre (2,-1)

Explanation:

x^2-4x+y^2+2y=11

Complete the square

(x-2)^2-4+(y+1)^2-1=11

(x-2)^2+(y+1)^2=16

(x-2)^2+(y+1)^2=4^2