Question

Use the equation below to find the center and radius of the circle.
x2 -2x +y2 -2y -23 =0
a. (-1,-1) r=23
b. (1,1) r= 23
c. (1,-1) r=25
d. (1,1) r =5

Answer 1

complete the square for both x and y

Answer 2

help me I don't know how to

Answer 3

for x you have x^2-2x=
\[(x ^{2}-2x+1)-1\]

Answer 4

that is
\[(x-1)^{2}-1\]
right?

Answer 5

similarly for y
y^2-2y=(y-1)^2 -1

Answer 6

then
\[(x-1)^{2}-1+(y-1)^{2}-1-23=0\]

Answer 7

can you try to continue ?

Answer 8

I can try

Answer 9

I really don't get the problem

Answer 10

ok
collect
-1-1-23=-25
and
then you ahve
(x-1)^2 +(y-1)^2=25
right?

Answer 11

ok im trying to find the radius and the center though