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:
2
Step-by-step explanation:
Please see attached picture for full solution.
Let the distance of Judy from intersection is x and distance of Jackie from intersection is y.
We convert the given information to equations, step by step.
Point 1: When Jackie is 1 mile farther from the intersection than Judy.
This means y is 1 mile more than x.
So,
y = 1 + x
Point 2: The distance between them is 2 miles more than Judy’s distance from the intersection.
Distance between is x+ y.
So, x+y is 2 miles more than y.
x+y = y + 2
⇒
x = 2
From point 1 we have:
y = 1 + x = 1+ 2 = 3
So,
Distance of Judy from intersection is 2 miles and distance of Jackie from intersection is 3 miles.
Answer: (2, -2)
Step-by-step explanation:
