To use De Moivre's theorem, we first write -2i is cis form: 0 - 2i has r = 2 and theta = 270.
Then we take the cube root, which means the new result will have r^(1/3), and the angle (theta/3). This means r = cbrt(2) and theta = 90.
This means that the answer is (cube root of 2)(cos90 + i*sin90), choice C.
I suspect the choices "3sqrt2" is actually a cube root of 2, not 3 multiplied by the square root of 2.
Scalene means uneven isosceles means two angles are even
Answer:
approximately 7 hours
see the explanation
Step-by-step explanation:
The picture of the question in the attached figure
Let
x ----> the time worked in hours
y ----> the amount earning in dollars
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form
or 
In a proportional relationship the constant of proportionality k is equal to the slope m of the line <u><em>and the line passes through the origin</em></u>
so
In this problem we have a proportional relationship
step 1
Find approximately how many hours would it take Delia to earn $250 ?
Looking at the graph
For y=$250 The value of x is approximately 7 hours
see the attached figure N 2
step 2
Find the exact value
from the graph take the point (5,175)
Find the value of k
----> 
The linear equation is

For y=$250
substitute

solve for x
