SOLUTION: What are the coordinates of centre of the circle given by the equation x square -4x +y square +4y=0 it looks something like this x 2 -4x+y 2 + 4y = 0? I just can't get the

Algebra ->  Functions -> SOLUTION: What are the coordinates of centre of the circle given by the equation x square -4x +y square +4y=0 it looks something like this x 2 -4x+y 2 + 4y = 0? I just can't get the       Log On


   

Question 1092459: What are the coordinates of centre of the circle given by the equation x square -4x +y square +4y=0
it looks something like this
x
2 -4x+y
2 + 4y = 0?
I just can't get the square in top of the x and y
thank you :0
Answer by ikleyn(52794) About Me  (Show Source):
You can put this solution on YOUR website!
.
x%5E2+-+4x+%2By%5E2+%2B+4y = 0        Use completing the squares for each group of x- and y-terms separately

%28x%5E2+-4x+%2B+4%29 + %28y%5E2+%2B+4y+%2B+4%29 = 4+%2B+4,

%28x-2%29%5E2 + %28y%2B2%29%5E2 = 16.


It is the standard equation of the circle of the radius sqrt%2816%29 = 4, centered at (2,-2).

See the lessons in this site
    - Standard equation of a circle
    - General equation of a circle
    - Transform general equation of a circle to the standard form by completing the squares
    - Identify elements of a circle given by its general equation

Also,  you have this free of charge online textbook in ALGEBRA-II in this site
    ALGEBRA-II - YOUR ONLINE TEXTBOOK.

The referred lessons are the part of this online textbook under the topic
"Conic sections: Ellipses. Definition, major elements and properties. Solved problems".