4,000,000,39
there you go!
Option C:
x = 90°
Solution:
Given equation:

<u>To find the degree:</u>

Subtract 1 + cos²x from both sides.

Using the trigonometric identity:




Let sin x = u

Factor the quadratic equation.

u + 2 = 0, u – 1 = 0
u = –2, u = 1
That is sin x = –2, sin x = 1
sin x can't be smaller than –1 for real solutions. So ignore sin x = –2.
sin x = 1
The value of sin is 1 for 90°.
x = 90°.
Option C is the correct answer.
This question doesent make sense
Answer:
The test statistic is 
Step-by-step explanation:
We are interested in determining whether or not the proportion of the student who experience anxiety during the exam is significantly more than 80%.
At the null hypothesis, we test if the proportion is 80%, that is:

At the alternate hypothesis, we test if the proportion is more than 80%, that is:

The test statistic is:

In which X is the sample mean,
is the value tested at the null hypothesis,
is the standard deviation and n is the size of the sample.
80% is tested at the null hypothesis:
This means that 
A random sample of 100 students was taken. Eighty-five of the student in the sample experienced anxiety during the exam.
This means that 
The test statistic is



The test statistic is 