How to solve Trignometry and Solution of Triangle questions

[snshusat161]

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.

 

[rock.freak667]

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.

 

[snshusat161]

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

 

[Mark44]

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"?

 

[snshusat161]

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

 

[snshusat161]

And then again invert the result to obtain h.m