1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
SpyIntel [72]
3 years ago
10

Write [2(cos15*+isin15*)]^3 in standard form a+bi

Mathematics
2 answers:
Marysya12 [62]3 years ago
8 0
Hello : 
by moivre theorem : 
[2(cos15*+isin15*)]^3 = 2^3(cos(3×45*)+isin(3×45*))
                                   =8 (cos45*+isin45*)
                                   = 8 ( √2/2 +i √2/2)
                                   = 4√2 + 4√2 i ..... ( <span>in standard form a+bi)
</span>a = b = 4√2 
Luda [366]3 years ago
6 0
<h2>Answer:</h2>

Hence, the standard form of the given expression is:

       [2(\cos 15+i\sin 15)]^3=4\sqrt{2}+4\sqrt{2}i

<h2>Step-by-step explanation:</h2>

We have to represent the expression:

[2(\cos 15+i\sin 15)]^3 in the standard form: a+bi

Now, this expression could also be written as:

[2(\cos 15+i\sin 15)]^3=2^3(\cos 15+i\sin 15)^3

i.e.

[2(\cos 15+i\sin 15)]^3=8(\cos 15+i\sin 15)^3

Now we will use the De Movier's Theorem that:

(\cos \theta+i\sin \theta)^n=\cos n\theta+i\sin n\theta

Hence, we have:

[2(\cos 15+i\sin 15)]^3=8(\cos (15\times 3)+i\sin (15\times 3))

i.e.

[2(\cos 15+i\sin 15)]^3=8[\cos 45+i\sin 45]

i.e.

[2(\cos 15+i\sin 15)]^3=8[\dfrac{1}{\sqrt{2}}+i\dfrac{1}{\sqrt{2}}]

i.e.

[2(\cos 15+i\sin 15)]^3=\dfrac{8}{\sqrt{2}}+i\dfrac{8}{\sqrt{2}}

i.e.

[2(\cos 15+i\sin 15)]^3=4\sqrt{2}+4\sqrt{2}i

You might be interested in
You play basketball at your school's
vaieri [72.5K]

Answer:

20 + 2x = 4x

Step-by-step explanation:

So you are setting the two expressions equal to each other.

buying a membership card  and paying each time looks like this: 20 + 2x where x is the number of times you go to the gym.  20 dollars base then 2 each time you go.

4 each time you go is just 4x

so just set the two equal to each other.

20 + 2x = 4x

If you solve it you will get x = something, which would be the number of times to make the two equal.  

8 0
3 years ago
The curved urface area of a cone i 140π cm2. What will be the radiu of a cone whoe lant height i 5 cm
VashaNatasha [74]

The radius of a cone with a curved surface area of 140π cm² and a slant height of 5 cm will be 28 cm.

<h3>What is curved surface area?</h3>

The region with just curved surfaces, leaving the circular top and base, is referred to as the curved surface area. Total Surface Area is the combined area of the bases and the curved surface. The measurement of a solid's curved surface area is its outer area, which excludes the top and bottom extensions. Surface area of the cylinder that is curved: A right circular cylinder is the solid that results when a rectangle circles around one side and makes a full revolution. The curved surface area of a cylinder (CSA) is also known as the lateral surface area and is defined as the area of the curved surface of any given cylinder having a base radius "r" and height "h".

Here,

Curved surface area of cone=πrl

=140π

l=5 cm

140π=πr*5

r=140/5

r=28 cm

The radius of cone that has 5 cm as slant height and 140π cm² as the curved surface area will be 28 cm.

To know more about curved surface area,

brainly.com/question/1037971

#SPJ4

7 0
1 year ago
The sum of the measures of angle Y and angle Z is 180 degrees. Angle Y measures (3x + 20) degrees and Angle Z measures x degrees
Minchanka [31]
A)
The question tells us that
y + z = 180
And
y=3x+20
z=x

So we put them in the first formula:

y + z = 180
(3x + 20) + x = 180

Add and get x to one side:
4x + 20 = 180
4x + 20 - 20 = 180-20
4x = 160
Divide both sides by 4
x = 40

B)
Put x back in to equation to get size of each angle:

Y =3x +20
Y=3(40)+20
Y=120+20
Y=140

Z=x
Z=40

Verify: y+z=180
140+40=180
180=180
8 0
2 years ago
How do you write 7% in the most simple fraction​
sesenic [268]

Answer:

The answer is 7/100 in a Simplified Fraction.

Step-by-step explanation:

Hope this helps!

6 0
2 years ago
Read 2 more answers
Terrance and his family are planning how to pay for his college education. The cost of tuition at his chosen college is $14,500
Finger [1]

Answer:

terrence will have to play 2900

Step-by-step explanation:

80% * 14500

14500-11600

2900

6 0
3 years ago
Other questions:
  • The top of a round table is 4 feet in diameter. The top splits to allow two extra boards to be inserted. The expansion boards ar
    15·1 answer
  • Find the total capacity of twenty five containers of cranberry juice if each bottle holds 5 quarts 1 pint 6 oz
    14·1 answer
  • 3/5+1/11 in simplest form
    5·1 answer
  • What is the equation of a line with slope of 3 and a y-intercept of 12?
    6·1 answer
  • Antony borrows $6.50 from a friend to pay for a sandwich and a drink at lunch. Then he borrows $3.75 from his sister to pay a li
    11·1 answer
  • The ratio of the measures of two complementary angle is 1:8, find the measure of each angle, the small and the large
    7·1 answer
  • Please help me this is my final exam i will give brainlist
    11·1 answer
  • <img src="https://tex.z-dn.net/?f=%20%5Cfrac%7B6%7D%7B7%7D%20%5Cdiv%207%20%5Cfrac%7B1%7D%7B2%7D%20%5Cdiv%20%3D%20" id="TexFormul
    13·1 answer
  • ¿cuáles son los criterios de congruencia y semejanza de triángulo?
    12·2 answers
  • Determine the distance between the two points (1, -3) and (-4, 3) plotted on the graph below.
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!