+0  
 
0
97
1
avatar+269 

 

ive been trying to solve this for a while but keep getting it wrong 

cerenetie  Feb 22, 2018
 #1
avatar+87294 
+2

x^2 + y^2 - 4x + 2y - 11  = 0

 

Rearrange as

 

x^2- 4x + y^2 + 2y  =  11

 

We need to complete the square on x  an y 

 

I'm assuming that you know how to do this...if, not...here's a good resource :

 

http://www.purplemath.com/modules/sqrcircle.htm

 

x^2 - 4x + 4 + y^2 + 2y + 1  =  11  + 4  + 1       factor and simplify

 

(x - 2)^2  +  (y + 1)^2   =  16

 

In the form    ( x - h)^2  + (y - k)^2  = r^2

 

The center  is  (h, k)   and the radius  = r  ......so....we can write

 

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

 

The center is   (2, - 1)   and the radius  is  4

 

 

cool cool cool

CPhill  Feb 22, 2018

12 Online Users

New Privacy Policy

We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive information about your use of our website.
For more information: our cookie policy and privacy policy.