• Nov 4th 2008, 02:26 AM
ea12345
find the radius and center of
• Nov 4th 2008, 02:28 AM
mr fantastic
Quote:

Originally Posted by ea12345
find the radius and center of

The general equation of a circle of radius r and centre at (h, k) is $(x - h)^2 + (y - k)^2 = r^2$.
• Nov 4th 2008, 02:35 AM
ea12345
urgent help
actual equation is
• Nov 4th 2008, 02:45 AM
mr fantastic
Quote:

Originally Posted by ea12345
actual equation is

Complete the square:

$(x + 4)^2 - 16 + 8 + y^2 = 0 \Rightarrow (x + 4)^2 + y^2 = 8$.

Now read again my first post.
• Nov 4th 2008, 02:49 AM
ea12345
x2 + y2 + 8x + 8 = 0
x2 + 8x + (4)2 + (y – 0)2 = -8 + x2
(x + 4)2 + (y – 0)2 = 8
(x – (-4) )2 +(y – 0)2 =( )
(x –(-x) )2 + (y – 0) = (2 )
SO, centre is (-4 , 0) and radius is 2

its true or not ?
• Nov 4th 2008, 02:51 AM
mr fantastic
Quote:

Originally Posted by ea12345
x2 + y2 + 8x + 8 = 0
x2 + 8x + (4)2 + (y – 0)2 = -8 + x2
(x + 4)2 + (y – 0)2 = 8
(x – (-4) )2 +(y – 0)2 =( )
(x –(-x) )2 + (y – 0) = (2 )
SO, centre is (-4 , 0) and radius is 2

its true or not ?