By using <span>De Moivre's theorem:
</span>
If we have the complex number ⇒ z = a ( cos θ + i sin θ)
∴
![\sqrt[n]{z} = \sqrt[n]{a} \ (cos \ \frac{\theta + 360K}{n} + i \ sin \ \frac{\theta +360k}{n} )](https://tex.z-dn.net/?f=%20%5Csqrt%5Bn%5D%7Bz%7D%20%3D%20%20%5Csqrt%5Bn%5D%7Ba%7D%20%5C%20%28cos%20%5C%20%20%5Cfrac%7B%5Ctheta%20%2B%20360K%7D%7Bn%7D%20%2B%20i%20%5C%20sin%20%5C%20%5Cfrac%7B%5Ctheta%20%2B360k%7D%7Bn%7D%20%29)
k= 0, 1 , 2, ..... , (n-1)
For The given complex number <span>⇒ z = 81(cos(3π/8) + i sin(3π/8))
</span>
Part (A) <span>
find the modulus for all of the fourth roots </span>
<span>∴ The modulus of the given complex number = l z l = 81
</span>
∴ The modulus of the fourth root =
Part (b) find the angle for each of the four roots
The angle of the given complex number =

There is four roots and the angle between each root =

The angle of the first root =

The angle of the second root =

The angle of the third root =

The angle of the fourth root =
Part (C): find all of the fourth roots of this
The first root =

The second root =

The third root =

The fourth root =
Answer:
0.21
Step-by-step explanation:
if you write it as a fraction it would be 21/100
and if that is made to a decimal it would be 0.21 .
Answer:
The answer to your question is 13 u²
Step-by-step explanation:
We know that the small triangle is surrounded by right triangles so we can use the Pythagorean theorem to find the lengths of the small triangle
AD² = 3² + 2²
Simplify
AD² = 9 + 4
AD² = 13
AD = 
Find the area of the square
Area = side x side
Area = AD x AD
Area = 
Area = 13 u²
Answer:
Thus the length = 230 and width = 90.
Step-by-step explanation:
Farmer Fernanda wants to put a fence around her rectangular field. The length of the field is 40 feet less than 3 times the width.
She has 320 feet of fencing.
Let the length of the rectangular fence be x and the width of the fence be y.
Then the relation between them is
x = 3y - 40
Also x + y = 320
Solving these equations,
320 - y = 3y - 40
4y = 360
y = 90
x = 230
Thus the length = 230 and width = 90.
Let’s find some exact values using some well-known triangles. Then we’ll use these exact values to answer the above challenges.
sin 45<span>°: </span>You may recall that an isosceles right triangle with sides of 1 and with hypotenuse of square root of 2 will give you the sine of 45 degrees as half the square root of 2.
sin 30° and sin 60<span>°: </span>An equilateral triangle has all angles measuring 60 degrees and all three sides are equal. For convenience, we choose each side to be length 2. When you bisect an angle, you get 30 degrees and the side opposite is 1/2 of 2, which gives you 1. Using that right triangle, you get exact answers for sine of 30°, and sin 60° which are 1/2 and the square root of 3 over 2 respectively.
Now using the formula for the sine of the sum of 2 angles,
sin(A + B) = sin A cos<span> B</span> + cos A sin B,
we can find the sine of (45° + 30°) to give sine of 75 degrees.
We now find the sine of 36°, by first finding the cos of 36°.
<span>The cosine of 36 degrees can be calculated by using a pentagon.</span>
<span>that is as much as i know about that.</span>