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.
Step-by-step explanation:
3
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Answer:
Step-by-step explanation:
9
1. ∠ACB ≅∠ECD ; vertical angles are congruent (A)
2. C is midpoint of AE ; given
3. AC ≅CE; midpoint divides the line segment in 2 congruent segments (S)
4.AB║DE; given
5. ∠A≅∠E; alternate interior angles are congruent (A)
6. ΔABC≅ΔEDC; Angle-Side-Angle congruency theorem
10
1. YX≅ZX; given (S)
2. WX bisects ∠YXZ; given
3. ∠YXW≅∠ZXW; definition of angle bisectors (A)
4. WX ≅WX; reflexive propriety(S)
5. ΔWYX≅ΔWZX; Side-Angle-Side theorem
Answer:
The area of the rectangle plus the area of the triangle under the line.
Step-by-step explanation:
