Sec 3 Maths Problem

• kkhing

  12 Jun 12, 13:21

  Hi,

  Can someone help me with the Maths below?

  Thanks.

  A Maths - Question 7 & 8

  

  E Maths - Part (C)

   

• wee_ws

  13 Jun 12, 08:38

  Hi,

    For Q7:

    1. Find the centre (say C) of the circle by completing the square (or otherwise).

    2. Draw a diagram containing the centre (C), the point M and the chord.

    3. Draw a line joining the centre and one end (say N) of the chord.

    4. Notice that we have a right-triangle with vertices CMN. Find the y-coordinate of N.

    5. With y-coordinate of N, find the equation of the chord.

    Thanks.

  Cheers,
  Wen Shih

• wee_ws

  13 Jun 12, 17:53

  Hi,

    For Q8:

    1. First, note that centre, say C, of the circle is (x, -2x - 1).

    2. Use the fact that the distances AC and BC are equal, to find x.

    3. With x found, coordinates of C and radius will be known and the equation of the circle can then be established.

    Thanks.

  Cheers,
  Wen Shih

• wee_ws

  13 Jun 12, 17:58

  Hi,

    For EM Q8:

    (a) Use Sine rule on isoceles triangle EBC.

    (b) Apply Pythagoras' theorem on right-triangle ABE.

    (c) Consider Cosine rule on isoceles triangle CAE and the result of (a).

    Thanks.

  Cheers,
  Wen Shih