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Homework Help: How to solve Trignometry and Solution of Triangle questions

  1. Apr 18, 2010 #1
    On my school days it was very simple because I used to take whatever I've and keep solving and by some or other ways I get succeed answering it but now as we are bounded by very less time (nearly a minute) so now I'm facing very hard time. How you know in which direction you need to go. I can't find a very correct direction to proceed by just looking at the equation's given.
  2. jcsd
  3. Apr 18, 2010 #2


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    Homework Helper

    I am not entirely sure what you mean.

    But once you are given a right angled triangle, firstly identify the hypotenuse and then for a given angle identify which sides are the opposite side and adjacent side.
  4. Apr 18, 2010 #3
    thanks, but that now I was asking. you have given a very limited answer. I want to know what come to mind when you see any questions of trigonometry. I know it is very difficult to tell what question strike our mind but for instance, I'm giving you one of the question from previous year paper.

    " Internal bisector of an angle A of triangle ABC meets side BC at D. A line drawn through D perpendicular to AD intersects the side AC at E and the side AB at F. If a, b, c represent the sides of triangle ABC then

    (a) AE is H.M. of b and c

    (b) AD = 2.b.c Cos (A/2)/(b+c)

    (c) EF = 4.b.c Sin (A/2)/(b+c)

    (d) The triangle AEF is isosceles
  5. Apr 18, 2010 #4


    Staff: Mentor

    The first thing that should come to mind is to draw a picture and labeling it using the given information. Hopefully that is obvious advice, but in my experience it is something that not all students do.

    BTW, what is "H.M. of b and c"?
  6. Apr 18, 2010 #5
    Harmonic mean of b and c. I'm on phone so i can't type latex code but take it as airth.. Mean of inverse of b and c
  7. Apr 18, 2010 #6
    And then again invert the result to obtain h.m
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