Results are out! Find what you need...fast. Get quick advice or join the chat
Hey there Sign in to join this conversationNew here? Join for free

C2 Coordinate geometry

Announcements Posted on
Complete this short survey for a chance to win an iPad mini! 22-09-2014
Got a question about Student Finance? Ask the experts this week on TSR! 14-09-2014
    • Thread Starter
    • 0 followers
    Offline

    ReputationRep:
    Here are the questions:

    1) The points A(-3,19), B(9,11) and C(-15,1) lie on the circumference of a circle. Find the coordinates of the centre of the circle.

    Midpoint = (-3+9/2, 19+11/2) = (-3,15)

    11-19/9+3 = -3/4

    4y=-3x+51

    Did the same for the other one, and got: M.P.(9,10) and 2y=3x-7

    (4y=-3x+51) + (2y=3x+7) -> 6y=44 -> y=44/6=22/3

    Is this right so far?

    2) Find the distance between (-4a,0) and (3a,-2a)

    d=√[(3a+4a)2+(-2a-0)2]
    =√[(7a)2+(-2a)2]
    =√[49a2+4a2 = √53a2

    Would the answer be √53a or 53a?
    • 3 followers
    Offline

    ReputationRep:
    It is 53a, because the square root cancels out with the squared. Remember it is \sqrt{(53a)}^2.
    • 63 followers
    Online

    ReputationRep:
    Sqrt{53}
    • 63 followers
    Online

    ReputationRep:
    (Original post by Math12345)
    It is 53a, because the square root cancels out with the squared. Remember it is sqrt(53a)^2
    No it isn't

Reply

Submit reply

Register

Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. By joining you agree to our Ts and Cs, privacy policy and site rules

  2. Slide to join now Processing…

Updated: April 7, 2012
New on TSR

TSR Freshers' blogs 2014

Read what TSR's freshers have to say as they head off to uni

Article updates
Reputation gems:
You get these gems as you gain rep from other members for making good contributions and giving helpful advice.