Revision Questions 3-Feb-2008

Q1 : If the two vertices of a triangle are (3,-1) and (-2,3) and its orthocentre is the origin, find the coordinates of the third vertex.

Q2 : Find the length of perpendicular drawn from (2,-1) on the line 3x+4y=12.

Q3 : Deduce the length of the perpendicular for the point (x1,y1) on the line ax+by+c=0. Given that (0,-c/b) is on Y-axis while (-c/a,0) is on x-axis. (Hint : using area of triangle to obtain the result).

Prizes : The person who can get the answers correctly  in the fastest of time will win a variety of red packets.

5 thoughts on “Revision Questions 3-Feb-2008

  1. Sir,examples 3 Q.8&9 can’t figure out!
    when can can u solve it?
    the rest questions really make me feel like to give up!
    Sir, i feel that my math become worse now!
    pressure~ ><

  2. I gave Q8(i) as an example this morning. Many still don’t understand the meaning of 1) incentre of a triangle 2) equation of the angle bisector…

    for Q9:

    step 1: sketch a simple graph for 3 vertices of a triangle ABC
    step 2: find the equation of AC
    step 3: find the equation of AB
    step 4: use the formula for two (+,-) for the angle bisector equations
    step 5: determine which one is a positive gradient and the answer!

    I think if i give you test (2) tomorrow u may ??? (^v^)…

  3. 老师,Q8(ii)还没有解喔!我试过去解,可是很奇怪,bisector算出来会有+-两个,但是一个没有x,一个没有y,那怎么取gradient?好奇怪啊!而且我看来看去还是看不出我错在哪里!!@@
    老师,剩两个星期就期考了,如果你要赶课不能一题一题解,你把答案放上来给我参考,不是步骤哦!我知道算的步骤,可是算出来的equations每次都怪怪的,不懂是我+-不分还是题目故意考倒我~
    所以麻烦你,解的时候把数据直接放上吧!^.^
    你放心,我不会直接用抄的!我会看到明白才抄^^
    谢谢你哦~再不然,你要是怕大家都上来抄答案没有自己做,那你email给我也ok!

  4. The reasons I don’t want to publish the solutions or notes here are:
    1. I have a scanner but I haven’t connected it to my PC yet! (This is the fastest way to publish many solutions to Ex. and many other notes)
    2. I don’t like to use the rapid-pi to type any notes and solutions because it takes too long to do these!

    Rapid-pi : this is a maths software to type all symbols and equations.

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