in the equation 2sin^2x- sqrt3 sin x= 0

Question

angle x may equal...

 

1. 0

2. 30

3. 45

4. 150

Answer 1

2sin²x - sinx√3 = 0

 

 

Factor out a sinx.

 

sinx(2sinx - √3) = 0

 

 

Set the factors equal to zero.

 

sinx = 0                  and                2sinx - √3 = 0

 

                                                   2sinx = √3

 

                                                     sinx = √(3) / 2

 

 

x = 0                                                 x = 60

x = 180                                             x = 180 - 60 = 120

x = 360

 

 

Out of all the choices, you can only have 0 degrees as your angle.

Answer 2

Answer is 0 because sin(0) is 0.

refer to: 

https://www.wyzant.com/resources/lessons/math/trigonometry/unit-circle/memorizing-coordinates

for values of common radian values.

i.e. cos(30⁰) = cos(pi/6) = sqrt(3)/ 2