A club is hosting a party split the kids into groups so there are equal number of children in each group

Find the complex fourth roots of 81(cos(3pi/8) + i sin(3pi/8))

BartSMP [9]

By using De Moivre's theorem:

If we have the complex number ⇒ z = a ( cos θ + i sin θ)
∴ $\sqrt[n]{z} = \sqrt[n]{a} \ (cos \ \frac{\theta + 360K}{n} + i \ sin \ \frac{\theta +360k}{n} )$
k= 0, 1 , 2, ..... , (n-1)

For The given complex number ⇒ z = 81(cos(3π/8) + i sin(3π/8))


Part (A) find the modulus for all of the fourth roots

∴ The modulus of the given complex number = l z l = 81

∴ The modulus of the fourth root = $\sqrt[4]{z} = \sqrt[4]{81} = 3$

Part (b) find the angle for each of the four roots

The angle of the given complex number = $\frac{3 \pi}{8}$
There is four roots and the angle between each root = $\frac{2 \pi}{4} = \frac{\pi}{2}$
The angle of the first root = $\frac{ \frac{3 \pi}{8} }{4} = \frac{3 \pi}{32}$
The angle of the second root = $\frac{3\pi}{32} + \frac{\pi}{2} = \frac{19\pi}{32}$
The angle of the third root = $\frac{19\pi}{32} + \frac{\pi}{2} = \frac{35\pi}{32}$
The angle of the fourth root = $\frac{35\pi}{32} + \frac{\pi}{2} = \frac{51\pi}{32}$

Part (C): find all of the fourth roots of this

The first root = $z_{1} = 3 ( cos \ \frac{3\pi}{32} + i \ sin \ \frac{3\pi}{32})$
The second root = $z_{2} = 3 ( cos \ \frac{19\pi}{32} + i \ sin \ \frac{19\pi}{32})$

The third root = $z_{3} = 3 ( cos \ \frac{35\pi}{32} + i \ sin \ \frac{35\pi}{32})$
The fourth root = $z_{4} = 3 ( cos \ \frac{51\pi}{32} + i \ sin \ \frac{51\pi}{32})$

7 0

3 years ago

A school has 600 pupils. 1/5 are in the upper school, 1⁄4 in the middle school and

crimeas [40]

Step-by-step explanation:

the number of pupils are in the lower school

= (1- 1/5 - ¼) × 600

= (20/20 - 4/20 - 5/20)×600

= (11/20) ×600

= 330 pupils

4 0

3 years ago

A die is thrown . find the probability of (1) a multiple of 2 or 3

tangare [24]

Answer:

A die is thrown which means that it can land on either 1-6 on the die.So if you want to find the probability of the multiple of 2 or 3....we have multiplies of 2 in the die from 1-6 which is 2,4 and 6 if you count them they are just 3 numbers and since there is a probability of it to land on any of them it will be 3/6 which is 1/2 if yiu divide by 3 to it's lowest term....Then multiple of 3 is 3,and 6.which will be 2/6 which is 1/3 if u cut to its lowest term. Or in the question means addition sign in probability then it is 2 or 3 which is (1/2)+(1/3)=5/6.Thank you for the question

7 0

3 years ago

Math Math Math Math help help help

Alchen [17]

Answer: 5a: 5/8

Step-by-step explanation: sorry, thats the only one i can read `:)

5 0

2 years ago

Read 2 more answers

The price of an item has dropped to

Deffense [45]

60% decrease.

$105-$42 = $63
$63/$105 = 0.6
0.6 x 100 = 60

8 0

3 years ago