Sin(4x) in the term of just x
Please help!!

Answers

Answer 1

I think you mean in terms of [tex]\sin(x)[/tex]?

Recall Euler's identity

[tex]e^{ix} = \cos(x) + i \sin(x)[/tex]

and de Moivre's theorem

[tex]\left(e^{ix}\right)^n = \left(\cos(x) + i \sin(x)\right)^n = \cos(nx) + i \sin(nx) = e^{inx}[/tex]

where [tex]i=\sqrt{-1}[/tex].

It follows that

[tex]\sin(4x) = \mathrm{Im}\left(\cos(x) + i \sin(x)\right)^4[/tex]

By the binomial theorem, expanding the right side gives

[tex]\cos^4(x) + 4i \cos^3(x) \sin(x) - 6\cos^2(x) \sin^2(x) - 4i \cos(x) \sin^3(x) + \sin^4(x)[/tex]

and so

[tex]\sin(4x) = 4\cos^3(x) \sin(x) - 4 \cos(x) \sin^3(x)[/tex]

We can factorize this as

[tex]\sin(4x) = 4 \cos(x) \sin(x) \left(\cos^2(x) - \sin^2(x)\right)[/tex]

and using the Pythagorean identity

[tex]\cos^2(x)+\sin^2(x) = 1 \implies \cos(x) = \pm \sqrt{1-\sin^2(x)}[/tex]

this reduces to

[tex]\sin(4x) = \pm 4 \sqrt{1-\sin^2(x)} \sin(x) (1 - 2 \sin^2(x))[/tex]


Related Questions




hi guys













i need help only 19​

Answers

y = 2/3x + 11/3

slope: (y2-y1)/(x2-x1) = (5-3)/(2- -1) = 2/3

point intercept form: (y-y1) = m (x-x1)
(y-3) = 2/3 (x+1)

solve for y
y-3 = 2/3x + 2/3
y = 2/3x + 11/3

Ms. Mathews wants to put a fence around the north, south and east sides if her square garden. The garden has an area of 100ft2. How much fencing does she need?

Answers

Answer:

30 feet

Step-by-step explanation:

3 sides of x feet each

area=x^2=100

x=10

10 x 3 = 30 feet

worth 30 points !!!!!

Answers

Answer:

a

Step-by-step explanation:

the line model shows 2 halfs of 4/10

The answer should be a

184329 rounded to the nearest 100

Answers

Answer:

184300

Step-by-step explanation:

Answer:

184300

Step-by-step explanation:

the tens place is less than 5 so the hundreds place will stay the same

(when rounding all numbers after the one being rounded will turn to 0)

Please help?
(3×+7)+(6+9)

Answers

Answer:

3x+22

Step-by-step explanation:

This might help for future questions as well

PLSSS HELPPP !!!At least how many square feet of canvas are needed to make one cover? (Use
A 44 ft.2
B 22 ft.2
C 770 ft. 2
D 154 ft.2

Answers

Answer:

154ft.2 witch is d

Step-by-step explanation:

i just know

On Monday, the baker makes 35 blueberry muffins.
What is the total number of muffins that the baker makes on Monday?

Answers

Answer:

We don't know

Step-by-step explanation:

enWe know that the baker makes 35 BLUEBERRY muffins BUT we do not know how many OTHER muffins he makes. If he just has blueberry, then he would be making 35.

Hope this helps! Have a great day :)

can someone help me find the area and perimeter please?​

Answers

Answer:

Step-by-step explanation:

Remember that the formula to get the area of a right triangle is base times height divided by 2, so to find the area:

5 x 12 = 60/2 = 30

Area of this triangle is 30.

To find the perimeter, add all the sides:

5 + 12 + 13 = 30.

Perimeter of this triangle is 30.

What is the slope of the line that contains these points? xxx -4−4minus, 4 -3−3minus, 3 -2−2minus, 2 -1−1minus, 1 yyy 222 555 888 111111

Answers

Given:

The table of values is

x        y

-4      2

-3      5

-2       8

-1       11

To find:

The slope of the line that contains these points.

Solution:

From the given table consider any two point.

Let the line passes through the points (-4,2) and (-3,5). So, the equation of the line is

[tex]y-y_1=\dfrac{y_2-y_1}{x_2-x_1}(x-x_1)[/tex]

[tex]y-2=\dfrac{5-2}{-3-(-4)}(x-(-4))[/tex]

[tex]y-2=\dfrac{3}{-3+4}(x+4)[/tex]

[tex]y-2=\dfrac{3}{1}(x+4)[/tex]

Using distributive property, we get

[tex]y-2=3x+12[/tex]

[tex]y=3x+12+2[/tex]

[tex]y=3x+14[/tex]

Therefore, the required equation of line is [tex]y=3x+14[/tex].

Answer: The slope is 1/5.

Step-by-step explanation:

You can find the answer by subtracting 6-1, (5) and 0-1,(1), which shows you 1/5. (Explanation sucks, sorry)

:)

PLease help!! I will give brainliest for the right answer!!

Answers

Answer:

angle CDE is 10 degree

Step-by-step explanation:

As angle C is 90

Angle E is equal to angle B which is 80 (180-100)

so 90+80+X=180

X=180-170

X=10

reflect...........................................

Answers

Answer:

F ( -1,4)

E (-1,2)

G (-4,5)

Step-by-step explanation:

Answer:

on what

.....................

HELP I forgot how to do this (show work please)

Answers

The answer is 23[tex]\sqrt{x} \pi[/tex].

Sorry that I didn't explain and made it short my annual examination is going on but I really wanted to help you.

What is the image of ( − 3 , − 5 ) after a reflection over the x-axis?

Answers

Answer:

(-3,5)

Step-by-step explanation:

In the slope 3/7, the 7 indicates to

Answers

Rise over run, so the seven indicates a change in 7 spaces to the right.

The ratio of two number is 4:9.When 5 is subtracted from each of them,the new ratio becomes 3:8. Find the numbers.

Answers

Answer:

The numbers are 20 and 45

Step-by-step explanation:

Let the two numbers be a and b

The ratio of the two is 4:9

That means;

a/b = 4/9

9a = 4b •••••(i)

secondly;

Subtracting 5 from each gives a ratio of 3:8

(a-5)/(b-5) = 3/8

8(a-5) = 3(b-5)

8a - 40 = 3b - 15

3b - 15 + 40 = 8a

3b + 25 = 8a

a = (3b + 25)/8 •••(ii)

Insert this into 1

9(3b + 25)/8 = 4b

27b + 225 = 32b

32b - 27b = 225

5b = 225

b = 225/5

b = 45

From i;

9a = 4b

9a = 4 * 45

a = 4 * 45/9

a = 20

cual es el resultado de -4+5/3​

Answers

Answer:

English translate so i can help you ? :)

Step-by-step explanation:

THIS IS GEOMETRY I ONLY ahve 10 MINUTES PLEASE HELP THANK U

Answers

Answer:

i need a photo or an equation TvT

Step-by-step explanation:

TvT TvT TvT

There’s not question thought :/

What is the volume of this?

Answers

Answer:

1728 m³

Step-by-step explanation:

[tex]A_{triangle}[/tex] = [tex]\frac{7.2*4.8}{2}[/tex] = 172.8 m²

V = 172.8 × 10 = 1728 m³

B is the midpoint of AC and AC=8r-20,and AB=3x-1
Find BC

Answers

Answer:

BC = 26

Step-by-step explanation:

since B is the midpoint of AC, then AB = BC

AC = 8x - 20 & AB = 3x - 1

AC = AB + BC or 2AB

8x - 20 = 2(3x - 1)

8x - 20 = 6x - 2

subtract 6x form each side

2x - 20 = -2

add 20 to each side

2x - 20 + 20 = -2 + 20

2x = 18

x = 9

BC = 3x - 1

BC = 27 - 1

BC = 26

AC = 52

why is it difficult to find fossilized plants and animals in the same place

Answers

Answer:  because the conditions to generate a fossil for an animal is very different from the conditions required for a plant.

Step-by-step explanation:

it is D

Answer:

d

Step-by-step explanation:

i think thats right. hope this helps

Please help explain. I’ve came up with 3 wrong answers

Answers

The answer is skdkdksjxsjdjsj hope this is what your looking for

Answer:

step 1. The volume of a cylinder (V) = (pi)R^2(h).

step 2. if the volume of a similar cylinder is 88ft^3 with R =2ft

step 3. then the cylinder with R = 5 would be (5/2)^2 bigger.

step 4. the volume of figure A is 88(5/2)^2

step 5. V = 88(5/2)^2 = 550ft^3.

The graph shows the number of each size T-shirt a store currently has in stock. Which statements are true?

Choose exactly two answers that are correct.

Question 3 options:

The ratio of large to small T-shirts is about 4 to 1.

There are more than 35 small and extra small T-shirts.

There are about twice as many large T-shirts as small T-shirts.

There are fewer than 100 T-shirts in all.

Answers

Answer:

medium, extra large

Step-by-step explanation:

BRAINLIEST PLEASE

there are fewer then 100 t shirts
the ration of large to small tshirts is about 4 to 1
they are both correct

Write the equation of the line that passes through the points (-4,8) and (-2, -1).
Put your answěr in fully reduced point-slope form, unless it is a vertical or horizontal
line.PLEASEEE HELPPP MEE

Answers

Answer:

y=-9/2x-10

Step-by-step explanation:

m=(y2-y1)/(x2-x1)

m=(-1-8)/(-2-(-4))

m=-9/(-2+4)

m=-9/2

y-y1=m(x-x1)

y-8=-9/2(x-(-4))

y-8=-9/2(x+4)

y=-9/2x-36/2+8

y=-9/2x-18+8

y=-9/2x-10

10 points
8. The ring system around Saturn has a diameter of 170,000 miles. Find
the circumference around the ring system, to the nearest whole number.
If Saturn diameter is 72,367 miles. What is the area of Saturn to the
nearest Whole number? *

Answers

Kfkfkkfkdkdkdkkd24.006

How many solutions does the system have?
You can use the interactive graph below to find the answer.
4x – 10y = –20
6x – 15y = -30

Answers

Answer:

Infinitely many solutions

Step-by-step explanation:

Answer:

infinitely many solutions

Step-by-step explanation:

cause khan academy said so

[tex](9x2-2x+1)-(3x2+5x-8)[/tex]

Answers

Answer:

(6x² - 7x + 9)

Step-by-step explanation:

Given:

(9x² - 2x + 1) - (3x² + 5x - 8)

Find:

Value of equation

Computation:

(9x² - 2x + 1) - (3x² + 5x - 8)

(9x² - 2x + 1 - 3x² - 5x + 8)

(6x² - 7x + 9)

The system of equations y=-3x+2 and y=1/2x-6 is shown on the graph below

Answers

Answer:

Step-by-step explanation:

What's the question?

A dealer of electric oven sold an induction heatet at Rs.4,200 with 13% VAT to a retailer. The retailer added transportation cost of Rs.250, profit 15% and local tax Rs.150 and sold to a costumer. How much will be paid for that heater if he/she has to pay 13% VAT​

Answers

Answer:

$6,619.42.

Step-by-step explanation:

Since a dealer of electric oven sold an induction heater at Rs. 4,200 with 13% VAT to a retailer, and the retailer added transportation cost of Rs. 250, profit 15% and local tax Rs. 150 and sold it to a costumer, To determine how much will be paid for that heater if the consumer has to pay 13% VAT, the following calculation must be performed:

((4,200 x 1.13) x 1.15 + 250 + 150) x 1.13 = X

((4,746 x 1.15) + 250 + 150) x 1.13 = X

(5,457.9 + 400) x 1.13 = X

5,857.9 x 1.13 = X

6,619.42 = X

Thus, the price to be paid by the consumer will be $ 6,619.42.

Myra is planning to purchase a recliner that costs 1,490 .the installment plan offered at the furniture store requires a 12% down payment and 20 monthly payments of $71 each .

Answers

Answer:

what is the question?

Step-by-step explanation:

Answer:

okay

Step-by-step explanation:

but whats the question tho u gave us the info so whats the question

Robert nixes yellow and blue paint in the ratio of three to two if he used 12 gallons of yellow paint how many gallons of blue paint would he use

Answers

Answer: 8 gallons of blue

Step-by-step explanation:

Robert mixes the paint in the ratio:

= 3 yellow : 2 blue

If there are 12 yellow used then direct proportion can be used:

3   :   2

12 :   x

Cross-multiplying will give:

3x = 24

x = 24 / 3

= 8 gallons of blue

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