Please prove the following trigonometric identity.

[tex]\cos^2(5x)-\sin^2(5x)=\cos(10x)[/tex]

Answers

Answer 1

Answer:

See Below.

Step-by-step explanation:

We want to verify the trigonometric identity:

[tex]\cos^2(5x)-\sin^2(5x)=\cos(10x)[/tex]

For simplicity, we can let u = 5x. Therefore, by substitution, we acquire:

[tex]\cos^2(u)-\sin^2(u)[/tex]

Recall the double-angle identity formula(s) for cosine:

[tex]\displaystyle \begin{aligned} \cos(2x)&=\cos^2(x)-\sin^2(x)\\&=2\cos^2(x)-1\\&=1-2\sin^2(x)\end{aligned}[/tex]

Therefore, our identity becomes:

[tex]=\cos(2u)[/tex]

Back-substitute:

[tex]=\cos(2(5x))=\cos(10x)\stackrel{\checkmark}{=}\cos(10x)[/tex]

Hence proven.

Answer 2

cos²A - sin²A = cos2A, this is a general indentity where A can have any random value x/2, y/3, 1/8, 8, 9 etc.

Replacing A with 5x:

=> cos²(5x) - sin²(5x) = cos²(10x)

Moreover,

cos(A + B) = cosAcosB - sinAsinB.

When A = B,

cos(A + A) = cosAcosA - sinAsinA

cos2A = cos²A - sin²A

You can do the same with 5x.

cos(10x) = cos(5x + 5x)

cos(10x) = cos(5x)cos(5x) - sin(5x)sin(5x)

cos(10x) = cos²(5x) - sin²(5x)


Related Questions

Calculate the volume of this triangular prism?

Answers

Answer:

960 sq cm

Step-by-step explanation:

(16*12*10)/2

Help shefeejhrhrhhtuy

Answers

Answer:

c. 80,360

Step-by-step explanation: multiply the number of cases they make each day by the amount of pastries each case contains

I need a answer ASAP​

Answers

Answer:

8

Step-by-step explanation:

y = (10x^2 + 3x^4)/ 2x^2

where x is not equal to 0

(20x + 12x)/4x

32x / 4x

= 8

a quadratic patterns has a second term equal to 1,a third term equal to -6 and fifth term equal to -14 .hence or otherwise calculate the first term of the pattern​

Answers

Answer:

first term of the pattern​ (T₁) : 10

Step-by-step explanation:

T₁  ;    1 ;    -6 ;   T₄ ;    -14  

1-T₁  ;  -6-1   ; T₄-(-6)  ; -14 -T₄    (First Tₙ-Tₙ₋₁)

-8+T₁  = T₄+13 = -2T₄-20            (2nd Tₙ-Tₙ₋₁ is constant)

T₄+13 = -2T₄-20          3T₄ = -33          T₄ = -11

-8+T₁  = T₄+13         -8 + T₁ = -11 + 13 = 2

T₁ = 10

all that make this true i need help

Answers

Answer:

D and E

Step-by-step explanation:

3(23+18)=123

6(18)=108.  6(19)=114.  6(20)=120.  6(22)=132.  6(24)=144

5th grade math. correct answer will be marked brainliest

Answers

Answer:

8 1/12 boxes

Step-by-step explanation:

Your first step to solve this problem is to convert those fractions to a common denominator. I would choose 12. So your first would be 4 4/12 and your second would be 3 9/12. You would then add those up and get 8 1/12 boxes of muffins bought at the bake sale.

Mast
Gabi tried to solve an equation step by step.
Skill
= 80
10
algeb
1
j
· 10 = 80 · 10 Step 1
10
ne-
j = 800
Step 2
Find Gabi's mistake.
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Choose 1 answer:
cual

Answers

Answer:

the answer is c

Step-by-step explanation:

Answer:

c

Step-by-step explanation:

Need help with this asap!!

Answers

Answer:

≈ 53.7° (Option 3)

Step-by-step explanation:

In the figure given above , the lengths of other two sides (excluding hypotenuse) are known to us. So , it would be convenient to use 'tan'.

Length of side opposite to angle 'x' = 15 cm

Length of side adjacent to angle 'x' = 11 cm

Using 'tan' formula - [tex]\tan x = \frac{Side \: opposite \: to \: x}{Side \: adjacent \: to \: x}[/tex] , lets solve this.

[tex]=> \tan x = \frac{15}{11}[/tex]

Using inverse tan function , lets find x.

[tex]=> x = {\tan}^{-1}(\frac{15}{11} )[/tex] ≈ 53.74°

Find the perimeter of the figure. due today

Answers

Answer:

24 in

Step-by-step explanation:

5in + 4in + 9in + 5in + (4in - 3in) = 24in

The length of a rectangle is increasing at a rate of 9 cm/s and its width is increasing at a rate of 4 cm/s. When the length is 15 cm and the width is 12 cm, how fast is the area of the rectangle increasing

Answers

Answer:

The area of the rectangle is increasing at a rate of 168 square centimeters per second.

Step-by-step explanation:

Geometrically speaking, the area of a rectangle ([tex]A[/tex]), in square centimeters, is described by following expression:

[tex]A = w\cdot l[/tex] (1)

Where:

[tex]w[/tex] - Width, in centimeters.

[tex]h[/tex] - Height, in centimeters.

By Differential Calculus, we find an expression for the rate of change of the area of the rectangle ([tex]\dot A[/tex]), in square centimeters per second:

[tex]\dot A = \dot w\cdot l + w\cdot \dot l[/tex] (2)

Where:

[tex]\dot w[/tex] - Rate of change of the width of the rectangle, in centimeters per second.

[tex]\dot l[/tex] - Rate of change of the length of the rectangle, in centimeters per second.

If we know that [tex]w = 12\,cm[/tex], [tex]l = 15\,cm[/tex], [tex]\dot w = 4\,\frac{cm}{s}[/tex] and [tex]\dot l = 9\,\frac{cm}{s}[/tex], then the rate of change of the area of the rectangle is:

[tex]\dot A = \dot w\cdot l + w\cdot \dot l[/tex]

[tex]\dot A = 168\,\frac{cm^{2}}{s}[/tex]

The area of the rectangle is increasing at a rate of 168 square centimeters per second.

Find the unit rate.. If a family travels in their mini-van for 465 miles and uses 15 gallons of gas what is the mileage per gallon?
10 points

Answers

465 miles 15 galons
x miles 1 gallon
x=465•1/15
x=465/15
x=31
Rate is 31 mirage per gallon

Need help on this question

Answers

Answer:

Step-by-step explanation:

arc between cars = 360°/25 = 14.4°

θ = 14.4° × π/180 ≅ 0.2512 radian

r = 150/2 = 75 ft

s = rθ = 75×0.2512 = 18.84 ft

area of circle = πr² = 75²π ≅ 17,662.5 ft²

area of sector = 17,662.5/25 = 706.5 ft²

jeremiah has a total of 144 pokemon cards 40 out of every 48 cards are not holographic cards at this rate how many of jeremiah cards are holographic

Answers

Answer:

120

Step-by-step explanation:

rate of a holographic card= 40/48=5/6.

Total number of holographic cards = 144*rate =144*5/6=120

Let X and Y be the following sets:
X = {10,20,30}
Y = {5, 10, 15, 20}
Which of the following is the set XY?

Answers

Answer:

{10;20}

Step-by-step explanation:

X & Y = {10;20}

can someone help me with this please​

Answers

Answer:

4

This figure has 4 lines of symmetry.


Jacque was selling bottles of water at the golf tournament Between 7 am and 8 am he sold 2 bottles of water, between 8 am and 9 am he sold 8 bottles, and between 9 am and 10 am he sold 32 bottles. If this trend
continues, how many bottles of water will he sell between 10 am and 11 am?
32
64
128
256

Answers

Answer:

128

Step-by-step explanation:

becuase 7-8 he sold 2

8-9 he sold 8

9-10 he sold 32

4*2= 8

4*2=32

4*32=128

factorise x^{2} +2x-24[/tex]

Answers

Answer:

(x + 6)(x - 4)

Step-by-step explanation:

x² + 2x - 24

(x + 6)(x - 4)

-4 and +6 multiply to 24 and add to +2.

is the table linear or not

Answers

Answer:

No, the table is not linear.

Step-by-step explanation:

Between the x and y there has to be a constant rate. There is no constant rate.

10 points!!!!!!! Plssssss helpppppp

Answers

The sports drink cost 1.25

A jar contains n nickels and d dimes. There is a total of 257 coins in the jar. The value of the coins is $17.35. How many nickels and how many dimes are in the jar?

Answers

Answer:

Here's what we know:

n + d = 20 (there are a total of 20 nickels and dimes)

.05n + .1d = 1.4 (total change equals $1.40)

There are a couple of ways to solve this. You can go the elimination method by multiplying the second equation by an amount to get rid of a variable, or we can go substitution by isolating a variable in the first equation. I'll go with elimination in this case:

-10(.05n + .1d = 1.4) this will cause the d-variable to equal 0:

n  +  d = 20

-.5n - d = -14

------------------

.5n = 6

n = 12

Now that we know n, we can solve for d:

12 + d = 20

d = 8

Check:

.05 * 12 + .1 + 8 = 1.4

.6 + .8 = 1.4

1.4 = 1.4

Step-by-step explanation:

(x+6)/(x+1)=6/2
Solving proportions

Answers

Answer:

[tex]x = \frac{3}{2} [/tex]

Step-by-step explanation:

[tex] \frac{x + 6}{x + 1} = \frac{6}{2} [/tex]

[tex] \frac{6}{2} = 3[/tex]

so, the solution of the equation will be as follows:

[tex] \frac{x + 6}{x + 1} = 3[/tex]

3(x+1) = x + 6

3x + 3 = x + 6

3x - x = 6 - 3

[tex]x = \frac{3}{2} [/tex]

so, the answer will be x = 3/2

9 and 11 need help
Mark brainlist

Answers

I will do 9 only. You can do 11.

Question 9

sin(60) = x/8

sin(60)(8) = x

4•sqrt{3} = x

x^2 + y^2 = 8^2

(4•sqrt{3})^2 + y^2 = 64

16(3) + y^2 = 64

48 + y^2 = 64

y^2 = 64 - 48

y^2 = 16

sqrt{y^2} = sqrt{16}

y = 4

Do 11 the same way.

PLZZZZ HELPPP MEE!!!!!

Answers

Answer:

-60

Explanation:

6x(2x-5) always do what's in the parentheses first

6x(-10)

= -60

What is the volume of the figure shown below?

Answers

Answer:

31 in

Step-by-step explanation:

Answer:

The volume of the figure shown below is 31 inches

Step-by-step explanation:

Just trust me ;)

Erin bought 4 jars of jelly and 6 jars of peanut butter for $19.32. Adam bought 3 Jars of jelly
and 5 jars of peanut butter for $15.67.
Use x for jars of jelly and y for jars of peanut butter, write the equation for either Erin or Jack.
DO NOT SOLVE
(Worth 10 points)

Answers

Here is your system of equations in two variables.

Equation for Erin:

4x + 6y = 19.32

Equation for Adam:

3x + 5y = 15.67

That's it.

El precio de cada acción de una empresa de tecnología ha presentado a través del tiempo un comportamiento dado por la siguiente función:



Donde t es el tiempo dado en días y A es el precio de la acción inicial cuando t = 0. Un inversionista desea conocer el número de días para el cual el valor de la acción se duplica. Para conocer este resultado, el proceso que se debe realizar es reemplazar f(t) por


A.
A/2, luego, expresar la ecuación en forma de logaritmo natural y ahora despejar t.

B.
2A, luego, expresar la ecuación en forma de logaritmo natural y ahora despejar t.

C.
2A, luego, dividir ambos lados de la ecuación por e y ahora despejar t.

D.
A/2, luego, dividir ambos lados de la ecuación por e y ahora despejar t.

Answers

I will ask you to turn it in english instead of española.

PLS HELP! (THE QUESTION IS A PICTURE CLICK ON THE QUESTION FIRST)

Answers

Answer:

Step-by-step explanation:

B.28.1

Answer:

It's BBBBBBBBBBBBBBBBB

simplify the expression by using the distributive property 3(7y+4)​

Answers

Answer:

3(7y+4) multiply the inner to 3 so, 21y+12

Hi there!

Let’s distribute 3 by multiplying it by everything inside the parentheses:

3 * 7y = 21

3 * 4 = 12

21y+12 (Answer)

Hope you find it helpful.

Feel free to ask if you have any doubts.

-Sparkle-

20% of __ = 18 Please help me Thank you Sooo Much

Answers

Answer: 20% of 90 = 18

Answer:

90%

Step-by-step explanation:

i hope this helps:)

can someone please help me find the area of a regular pentagon of radius 4m? thank you :(

Answers

Answer:38.07

Step-by-step explanation:

If you don't have the apothem value, you will need more information to find the area accurately. The radius alone does not provide enough information to find the area of the regular pentagon.

To find the area of a regular pentagon with a given radius, we need to know the apothem (the distance from the center of the pentagon to the midpoint of one of its sides) in addition to the radius. However, you mentioned only the radius, and it is not sufficient to directly find the area.

If you have the apothem value, you can use the following formula to calculate the area of a regular pentagon:

Area = (5/4) * apothem * side length

To know more about area:

https://brainly.com/question/28995006

#SPJ2

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