March 26

Week6 — Math 10

This week I learnt Trigonometric Ratios. From the questions on the workbook, I summed up some rules:

Rule I1) sin x˚, sin y˚,  if x>y, so  sin x˚>sin y˚

2) cos x˚, cos y˚, if x>y, so cos x˚<cos y˚

3) tan x˚, tan y˚, if x>y, so tan x˚>tan y˚

4) sin x˚, tan x˚, so sin x˚< tan x˚.

Rule II: sin x˚, cos x˚

1) x<45˚               sin x˚< cos x˚

2) x=45˚              sin x˚= cos x˚

3) x>45˚              sin x˚> cos x˚

There is also a very important rule is cos x˚=sin (90 – x)˚ and sin x˚=cos (90 – x)˚.