Hello there!! We meet again today and you know what?? It's NEW YEAR!!! Welcome 2014... And Good Bye 2013... May our dreams and wishes come true for this year... And now, I'm gonna teach everyone of you who read this post bout' simple and easy steps for mastering special angles in TRIGONOMETRY!
I really hope most of you LOVE this topic especially for Engineer Students haha!! As well, some of you I expect might say :
well.......... That's normal for most of US!
You might END UP being like THIS SILLY PATHETIC GIRL if you always memorizing something without making it simple and easier to understand especially those BEAUTIFUL and GLITTERY special Angles table above! Yep! you DON'T have to MEMORIZE all of them bcuz' it will build stress on your head simultaneously making you HATE this topic! Luckily!! There's solution for your problems that will come in handy when it comes to exam!!! BEWARE!! The exam paper does not cover formulas and special angles value!
HERE THE STEPS FOR THE SPECIAL ANGLE TRICK!
- Prepare your LEFT HAND! and set it up like this picture...
BE Alert! this picture shows a right hand! Set ur LEFT PALM in front of you where the fingers heading towards ur right, then instead using the angles in the picture flip the angles just like the info below:
thumb = 90 degree
index finger = 60 degree
middle finger = 45 degree
ring finger = 30 degree
little finger = 0 degree
NOTE : The reason why I choose LEFT hand is bcuz' most of people use their right hand for writing during examination.. Thus, using this trick would be faster if using another left hand instead of using the same hand for writing and counting ..
- Next, set the formula of surd x divide by 2 on your palm
Note : Again the picture shows a right hand.. Like I said, just use the left hand to make you easy to use this whenever the time is CRUCIAL especially during the examination. Just follow the formula. And let the hand in the picture be your LEFT hand with the palm facing your face with this order :
Thumb : 90
Index finger : 60
Middle finger : 45
Ring finger : 30
small finger : 0
unknown x : indicate the number of fingers depend on trigonometry question.
remember the direction of SINE is from 90 to 0...
and direction of COSINE is from 0 to 90 .
- Remember this formula
those formula has a close relationship with those direction of SINE and COSINE earlier.. Then What are you waiting for? Let's warm up!
EXAMPLE :
Quest. : cos 30
when the question is "cosine" the direction is from 0 to 90 degree.. using ur left palm, close "ring finger" becuz' it indicate the "30 degree".. using the formula above, upper fingers from the 30 degree's finger is counted as substitute for the unknown "x" in the formula of surd x divide by 2 which is x = 3 . Then you will get the answer which is surd 3 over 2 .
Quest. : sin 45
here again the question is different which is "sine". The direction of sine is from 90 to 0. Do the same thing as earlier, close 45's finger and the lower finger from it is 2 fingers make the x = 2 . Thus will make the answer surd 2 over 2 .. Easy right? GOOD LUCK!
Question :
- cos 45
- cos 60
- sin 30
- sin 90
- tan 45
- tan 30
The Answer for these questions is in the Table at the TOP of the post!! Tq... :) LOL
Hopefully the tricks GIVEN really work for your trigonometry special angles assessments... and for those Trigonometry basic, compound and double angles formula, you need to work hard to get used of it.. This trick really helpful when it comes to "without using calculator" .. hahaha.. GOOD LUCK~
Any questions just ask me or leave your comment below~
