Respuesta :
Answer: cos of theta= square root 3//2 and the measure of the reference angle is 30
Step-by-step explanation:
11π/6 reference angle is π/6 which is 30 degree so the measure of the reference angle is 30 degrees is correct. sin of 330 is sqr root of 3 divided by 2. Since it in the 4th quadrant and cos refers to x -axis it is positive.
The following options are correct:
The measure of the reference angle is: [tex]30 ^o[/tex]
[tex]\cos(\theta) = \frac{\sqrt 3}{2}[/tex]
The reference angle of an angle is the smallest acute angle between the terminal arm of a quadrant and the x-axis.
Given that:
[tex]\theta = \frac{11\pi}{6}[/tex]
First, we convert to degrees
[tex]\theta = \frac{11\pi}{6} * 180\pi[/tex]
[tex]\theta = \frac{11}{6} * 180[/tex]
[tex]\theta = 11 * 30[/tex]
[tex]\theta = 330^o[/tex]
Since 330 is closer to 360, the reference angle ([tex]\alpha[/tex]) is:
[tex]\theta = 360 - \alpha[/tex]
Substitute [tex]\theta = 330^o[/tex]
[tex]330 = 360 - \alpha[/tex]
Collect like terms
[tex]\alpha= 360 - 330[/tex]
[tex]\alpha= 30[/tex]
Hence, the measure of the reference angle is: [tex]30 ^o[/tex]
[tex]\alpha= 30[/tex] means that the reference angle is in the first quadrant
[tex]\theta = 330^o[/tex] means that this angle is in the fourth quadrant
In the first and the fourth quadrants,
[tex]\cos(\theta) = \cos(\alpha)[/tex]
Substitute [tex]\alpha= 30[/tex]
[tex]\cos(\theta) = \cos(30)[/tex]
In trigonometry:
[tex]\cos(30) = \frac{\sqrt 3}{2}[/tex]
So:
[tex]\cos(\theta) = \frac{\sqrt 3}{2}[/tex]
Read more about reference angles at:
https://brainly.com/question/1603873