1 cos2x12 2 cos4x1 3 cotx2sqrt3 4 csc3x2 5 cosx3sqrt32 6 cot
1. cos(2x)=1/2
2. cos(4x)=-1
3. cot(x/2)=sqrt(3)
4. csc(3x)=2
5. cos(x/3)=-sqrt(3)/2
6. cot(5x)=-sqrt(3)
answer in form x=___+___pi*n
Solution
1. cos(2x)=1/2
2x = cos^-1(1/2)
2x = pi/3 ---> x = pi/6
2x = 2pi -pi/3 = 5pi/3
x = 5pi/6
Solution : x = pi/6 +2pi*n
x = 5pi/6 +2pi*n
2. cos(4x)=-1
4x = cos^-1(-1) =pi-pi/4 , pi+pi/4
x = 3pi/16 , x = 5pi/16
Solution : x = 3pi/16 +2pi*n
x = 5pi/16 +2pi*n
3. cot(x/2)=sqrt(3)
tan(2x) = 1/sqrt3
2x = pi/6 , 7pi/6
x = pi/12 , 7pi/12
Gen solution : x = pi/12 +pi*n ; x = 7pi/12 +pi*n
4. csc(3x)=2
sin(3x) =1/2
3x = pi/6 , 5pi/6
x = pi/18 , 5pi/18
Gen solution : x = pi/18 +2pi*n
x = 5pi/18 +2pi*n
