Results 1 to 3 of 3

Math Help - finding radius/center of circle

  1. #1
    Newbie
    Joined
    May 2008
    Posts
    4

    finding radius/center of circle

    find the radius r and the center (h,k) of the following circle
    2 2
    3 (x-3) + 3y =75
    Last edited by shawn9356; June 4th 2008 at 12:36 PM. Reason: my number 2's not positing right
    Follow Math Help Forum on Facebook and Google+

  2. #2
    is up to his old tricks again! Jhevon's Avatar
    Joined
    Feb 2007
    From
    New York, USA
    Posts
    11,663
    Thanks
    3
    Quote Originally Posted by shawn9356 View Post
    find the radius r and the center (h,k) of the following circle
    2 2
    3 (x-3) + 3y =75
    do you mean 3(x - 3)^2 + 3y^2 = 75?

    if so, note that this is: (x - 3)^2 + y^2 = 5^2

    Now, when a circle is written in the form (x - h)^2 + (y - k)^2 = r^2, the center is (h,k) and the radius is r. i leave the rest to you
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Moo
    Moo is offline
    A Cute Angle Moo's Avatar
    Joined
    Mar 2008
    From
    P(I'm here)=1/3, P(I'm there)=t+1/3
    Posts
    5,618
    Thanks
    6
    Hi !

    Quote Originally Posted by shawn9356 View Post
    find the radius r and the center (h,k) of the following circle
    2 2
    3 (x-3) + 3y =75
    Use ^2 to write exponents

    You know that the equation of a circle, of center O(x_O ~,~y_O) and of radius R is :

    (x-x_O)^2+(y-y_O)^2=R^2

    Therefore, try to make appear that form.

    The reflex will be to divide the whole equation you have by 3, in order to get (x-3)^2+y^2=\dots

    Then, note that y=y-0.
    Recognize in your equation x_O, y_O and R
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 1
    Last Post: July 22nd 2010, 10:34 AM
  2. Replies: 1
    Last Post: June 8th 2010, 04:44 PM
  3. Replies: 7
    Last Post: March 15th 2010, 04:10 PM
  4. center and radius of a circle?
    Posted in the Pre-Calculus Forum
    Replies: 4
    Last Post: January 29th 2009, 09:46 PM
  5. Finding Center And Radius of Circle
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: May 12th 2008, 01:13 PM

Search Tags


/mathhelpforum @mathhelpforum