Originally Posted by
MP3
Oh yea for the previous question i asked you, why does sin thetha =  sqrt of 3 /2 belong to the third and fourth quadrant?
Code:
y
2nd Q  1st Q


x
0 
3rd Q  4th Q

Sin is positive in the 1st and 2nd Quadrant.
Cos is positive in the 1st and 4th Quadrant.
Tan is positive in the 1st and 3rd Quadrant
Cot is positive in the 1st and 3rd Quadrant
so if you have an expression $\displaystyle cos^{1} (\frac {\sqrt{2}}{2})$ you know that the solution is in the 2nd and 3rd Quadrant because its negative there.
$\displaystyle sin \Theta = \frac{\sqrt{3}}{2} $
From the minus you know that the solution will be in the 3rd and 4th Quadrant.
$\displaystyle \Rightarrow \Theta_{1} = 0^0  60^0 = 60^0 = 300^0 $
$\displaystyle \Theta_{2} = 180^0 + 60^0 = 240^0$