O level Elementary Maths Trigo Question

• syncopation_music

  1 Jun 09, 11:51

  hi ,need help to find the tan angle in this question

   

  thanks for the help

  

   

• Lee012lee

  1 Jun 09, 12:43

  "O" level E.Maths students tend to think only about TOA CAH SOH for acute angle only.

  In fact, there is the TOA CAH SOH for obtuse angle too.

  tan angle EBC is an obtuse angle TOA.

  Hence, tan angle EBC = - 5/12.

  PS : "O" level Add Maths students will know that TOA CAH SOH can be for all 4 quadrants ie the famous ASTC (add sugar to coffee, all science teachers are crazy etc) rule.

• SBS n SMRT

  1 Jun 09, 21:12

  still got cot (x) and so on..AS is for EM, ASTC is for AM...hehe..AM students got advantage
• tr@nsp0rt_F3V3R

  1 Jun 09, 21:16

  speaking of ASTC. we got better version... :)

• tr@nsp0rt_F3V3R

  1 Jun 09, 21:18

  give me a gal's name starting with A and a boys name starting with T... best is someone in the class

  so it looks sth lyke that

  adele suck Thomas Co#k

  ASTC

• syncopation_music

  1 Jun 09, 21:26

  Originally posted by tr@nsp0rt_F3V3R:

  give me a gal's name starting with A and a boys name starting with T... best is someone in the class

  so it looks sth lyke that

  adele suck Thomas Co#k

  ASTC

  that dirty ....wahaahahaha

   

  :)

• eagle

  2 Jun 09, 00:46

  Originally posted by tr@nsp0rt_F3V3R:

  give me a gal's name starting with A and a boys name starting with T... best is someone in the class

  so it looks sth lyke that

  adele suck Thomas Co#k

  ASTC

  just like physics... what my physics told me last time for visible light, backwards, then modified by my students -.-"

  Virgins
  In
  Bed
  Give
  You
  Orgasmic
  Reactions

  Got one more dirtier one given by one of my students last year... but I forgot liao
  

• eagle

  2 Jun 09, 00:47

  Originally posted by Lee012lee:

  "O" level E.Maths students tend to think only about TOA CAH SOH for acute angle only.

  In fact, there is the TOA CAH SOH for obtuse angle too.

  tan angle EBC is an obtuse angle TOA.

  Hence, tan angle EBC = - 5/12.

  PS : "O" level Add Maths students will know that TOA CAH SOH can be for all 4 quadrants ie the famous ASTC (add sugar to coffee, all science teachers are crazy etc) rule.

  very true
  need to help switch their mindset to include obtuse angles too

  Finding AD also very important... using areas...
  Not only used here, many other question types as well...