Sec 3 Term 3

Trigonometrical Ratio

Let's have some fun listening to this trigonometry song.

Main Course :
a) The Unit circle
This mnemonic stands for:
  • Sine is Opposite over Hypotenuse
  • Cosine is Adjacent over Hypotenuse
  • Tangent is Opposite over Adjacent

When two ratios have the same name other than the "co-" at the start of one of them, the pair are called "co-functions". (Note: The ratios didn't get their current names until the 12th century or so, as a result of Europeans making some mistakes when they translated Arabic texts.)
  • cosec is 1 over Sine
  • sec is 1 over Cosine
  • cot is 1 over Tangent

i) View through this video to establish the relationship between trigonometrial ratio and a unit circle.

In summary , these are the 6 important trigonometrical ratio that you must know.


Note: csc = cosec

These are the special angles and their respective trigonometrical ratio that you must know in the various values.

Note : U = undefined

b) You should have this set of slides. If yours is ..., click on the link below to reprint another set. Do bear in mind that in doing so you are harming the pitiful trees in the woods.
You must go through all the examples in this set of slides to ensure that you have mastered the respective basic content knowledge.

c) With these newly acquired knowledge, you may proceed to attemp the textbook exercises.

Exercise 11.1 (pg 228) : Q1, Q3, Q4 (change to degree pi/2=90 deg), Q5a, 5b, Q6, Q7

Exercise 11.2 (pg 235) : Q 2a, Q2f, Q2h, Q3, Q4, Q6, Q7a, b,c,d,e,f

a) You should have a copy of this assignment, if yours is missing ! Print a copy here . Bear in mind of saving our mission of saving "Mother Earth". Please do you part.

b) Let's have some fun here. Create a mathematical stamp that relates the various trigometrical ratios that you have mastered. There is an example of a mathematical stamp.


Create your mathematical stamp and upload your illustration here.
Have fun!