Answer: 
=========================================================
Explanation:
Use the pythagorean trig identity
and plug in the fact that 
Isolating sine leads to
. I'm skipping the steps here, but let me know if you need to see them.
The result is negative because we're in quadrant 4, when y < 0 so it's when sine is negative.
Therefore,

Answer:
C. f has a relative maximum at x = 1.
Step-by-step explanation:
A. False. f(x) is concave down when f"(x) is negative. f"(x) is the tangent slope of the graph, f'(x). So f(x) is concave down between x = -1.5 and x = 1.5.
B. False. f(x) is decreasing when f'(x) is negative. So f(x) is decreasing in the intervals x < -3 and 1 < x < 2.
C. True. f(x) has a relative maximum where f'(x) = 0 and changes from + to -.
Actually I can help you in three of them as the number "3" is not confined between the arrays ND and NE
So:
It would be
angle END
or
angle DNE
or
angle N
Answer:
The minimum sample size needed is 125.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.

In which
z is the zscore that has a pvalue of
.
The margin of error is:

For this problem, we have that:

99% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
What minimum sample size would be necessary in order ensure a margin of error of 10 percentage points (or less) if they use the prior estimate that 25 percent of the pick-axes are in need of repair?
This minimum sample size is n.
n is found when 
So






Rounding up
The minimum sample size needed is 125.
If arctan 4/3 = the tangent of that angle will be 4/3 , opposite 4 over adjacent 3
Now, you only have to take the sin of that angle it's opposite 4 over hypotenuse 5.
You will get that the answer is 4/5
hope this helps