Answer:
$98.10
Step-by-step explanation:
150 decrease 40% =
150 × (1 - 40%) = 150 × (1 - 0.4) = 90
90 increase 9% =
90 × (1 + 9%) = 90 × (1 + 0.09) = 98.1
Answer:
The answer would be A)98.
I got this by taking the 3 test scores that were provided and adding them then subtracting that by 360 (90x4 - which would give you a 90 in the end) so I had 360 - 262 which equaled 98 and that would be the score needed to have a 90 in the end.
Answer:
Step-by-step explanation:
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.
