9. You need an exact answer. So I will give you it but I'll also give you an approximation because it might help you understand it more.
Because we know the cosine fo theta, we can evaluate the inverse cosine of -2/3 first to find theta.
= 131.81° approx.
Because 131.81° is in the second quadrant its third quadrant partner is 228.19°. Which would make the sine 0.75 approximately.
But we need an exact answer I suppose so which is this disgusting mess...
. I know it looks scary but it is basically all the steps we just did but without evaluating anything.
This can be simplified using: sin(x− y) = sinxcosy−cosxsiny
To... 
answer: 
10. Okay. So because we have a point we can say that...
θ = 
sin(θ) = +sin(
)
11. arcsin(-0.37) =
= -21.72°+2kπ or 201.72°+2kπ approx. where k has to be an integer
answer: idk if you want one or more solutions so I gave you them all.
12. arccos(-√3/2) = 
Remember that "k" must be an integer.
answer: 5π/6
Step-by-step explanation:
For example, 1/2 and 2/4 are equivalent fractions. If you simplify 2/4 by dividing both the numerator and denominator by 2, you'll get 1/2, the same as the other one. Remember, our number line is a line with evenly spaced tick marks that show us our numbers.
Considering that the hypothesis test found an statistically significant result, it is found that the correct option is:
c. probability of obtaining this finding by chance alone is less than some quantity.
<h3>What is an hypothesis test?</h3>
- When a hypothesis test, there are two hypothesis, the null and the alternative hypothesis.
- There is also a significance level.
- If the probability of obtaining the finding by chance is less than the significant value, the result is statistically significant.
Hence, according to these bullet points, option C is correct.
You can learn more about hypothesis tests at brainly.com/question/16313918
Answer: 
Step-by-step explanation:
All radii of a circle are congruent, so by the base angles theorem
Also, angles x and y are inscribed in the same arc, and they are thus congruent, meaning x = 65.