In this week of pre calc were working on Trigonometry. We worked on finding Sin, Cos and Tan of different angles. We got familiar with Unit Circle which its radius is one. We can find our ratios by using this circle.
Sin = y/r Cos = x/r Tan = y/x
or we can use:
Sin = opposite/hypothesis Cos = adjacent/hypothesis Tan = opposite/adjacent
I found out about relationship between the ratios. If we divide Sin on Cos, it will be : Sin/Cos = (opp/hyp) / (adj/hyp)
Sin/Cos = opposite/adjacent (which is equal to Tan)
*So, if we divide Sin of an angle on its Cos we can find the Tan of that angle!*
Unit circle has 4 quarters. In every quarter the signs of our ratios are different.
-Quarter 1: x>0 , y>0
Sin>0 , Cos>0 , Tan>0
-Quarter 2: x<0 , y>0
Sin>0 , Cos<0 , Tan<0
-Quarter 3: x<0 , y<0
Sin<0 , Cos<0 , Tan>0
-Quarter 4: x>0 , y<0
Sin<0 , Cos>0 , Tan<0