Answer:
Step-by-step explanation:
Firstly, note that -2i really is just z = 0 + (-2)i, so we see that Re(z) = 0 and Im(z) = -2.
When we're going from Cartesian to polar coordinates, we need to be aware of a few things! With Cartesian coordinates, we are dealing explicitly with x = blah and y = blah. With polar coordinates, we are looking at the same plane but with angle and magnitude in consideration.
Graphing z = -2i on the Argand diagram will look like a segment of the y axis. So we ask ourselves "What angle does this make with the positive x axis? One answer you could ask yourself is -90°! But at the same time, it's 270°! Why do you think this is the case?
What about the magnitude? How far is "-2i" stretched from the typical "i". And the answer is -2! Well... really it gets stretched by a factor of 2 but in the negative direction!
Putting all of this together gives us:
z = |mag|*(cos(angle) + isin(angle))
= 2*cos(270°) + isin(270°)).
To verify, let's consider what cos(270°) and sin(270°) are.
If you graph cos(x) and look at 270°, you get 0.
If you graph sin(x) and look at 270°, you get -1.
So 2*(cos(270°) + isin(270°)) = 2(0 + -1*i) = -2i as expected.
Answer: F. Statistic, because the data set of salaries of 50 employees is a sample.
Step-by-step explanation:
A parameter gives measure of a characteristic for the entire population where as a statistic gives measure of a characteristic for the subset of population (sample).
Given : The average annual salary of 50 of a company's 800 employees is $54,000.
It means the sample size = 50 and the sample mean salary= $54,000.
i.e $54,000 is giving the measure for mean salary for the sampled 50 employees.
It means $54,000 is a statistic .
Hence, the correct answer is option (F).
Answer:2/16
Step-by-step explanation:
You start with 2x -5>7 the you add five to both sides 2x-5+5>7 +5 2x.12 then divide both sides by 2 2x divided by 2 > and 12 divided by 2 and get x>6
