Question

Find two solutions of each equation. Express the results in radians.?
1.) CosX= (square root of 2) / 2
2.) CosX= -(square root of 2) / 2
3.) TanX= 1
4.) CotX= -(square root of 3)

Answer 1

1) cos(x)=√2/2
arccos(√2/2)=x
x= π/4 or 7π/4

2) cos(x)=-√2/2
arccos(-√2/2)=x
x= 3π/4 or 5π/4

3) tan(x)=1
arctan(1)=x
x= π/4, 5π/4

4) cot(x)=-√3
1/tan(x)=-√3
-√3*tan(x)=1
tan(x)=-√3/3
x= 5π/6 and 11π/6

Answer 2

http://3.bp.blogspot.com/_K08TBb-wm10/TIkX5rNJSoI/AAAAAAAAAWA/dT0DuR-YbYY/s1600/unit+circle.jpg

Answer 3

awesome thanks !