Mr. Lai’s Math Blog

student tutorials on math contest questions

2006 Question #23 (by Gurbir P.)

Posted by elai on October 19, 2008




4 Responses to “2006 Question #23 (by Gurbir P.)”

  1.   Powl Vosper Says:

    i found it really helpful when at about 2 minutes you kind of summarised everything you did, it really helped me understand. But the one thing i didn’t get is where you got the triangle and the angles at about 3:30, was it the one from the problem or just some random triangle?

  2.   Ridzwan Nur Saidy Says:

    At 3:31,you tried to explain where you get the (-1/√2), saying that it came from the “special” triangle. Where did the the triangle come from in the diagram? Other than this, a job well done on the presentation.

  3.   Anne Liu Says:

    when you try to explain how you get the cosine: negative 1 over root 2, you draw a triangle, but how do you know the bottom is negative 1 ?

  4.   Kristy Yang Says:

    I would just like to clarify whether the line segment, 3t, is from J to C or J to H? Also, if you use the quadratic formula (-b+/-rootb^2-4ac)/ 2a) to solve for t, then shouldn’t you have 2 answers?

Leave a Reply

Create a free edublog to get your own comment avatar (and more!)

XHTML: You can use these tags: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>

*
To prove you're a person (not a spam script), type the security word shown in the picture.
Anti-Spam Image