Answer:
6.5e^(i·(-157.38°)) ≈ 6.5e^(-2.7468i)
Step-by-step explanation:
A suitable calculator can find the value of this ratio for you.
((2+3i)/(1-i))² = -6 -2.5i ≈ 6.5∠-157.38° ≈ 6.5e^(-2.7468i)
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The second attachments shows the calculator set to radian mode for the angle measure.
Answer:
21
Step-by-step explanation:
Using<em> Simple Random Sampling</em>, we can estimate the sample size by the formula
where
n = sample size
Z = the z-score corresponding to the confidence level 99.5%
S = the assumed standard deviation = 3 seconds
e = margin of error = 2 seconds
<em>It is worth noticing that the higher the confidence level, the larger the sample should be. </em>
The z-score corresponding to a confidence level of 99.5% can be obtained either with a table or the computer and equals
Z = 3.023
Replacing the values in our formula
So the size of the sample should be at least 21.