prove that (Cos A +cosB)^2+(SinA+sinB)^2=4cos^2(A-B/2)

Answers

Answer 1

Answer:

[tex](cosA + cos B)^2 + (sin A +sinB)^2 \\\\= cos^2A + cos^2B + 2cosA cosB + sin^2A +Sin^2B +2sinAsinB\\\\=(cos^2A + sin^2 A) + (cos^2B +sin^2B) +2cosAcosB + 2sinAsinB\\\\= 1 + 1 + 2cosAcosB + 2sinAsinB\\\\=2 + cos(A+B)+cos(A-B) + cos(A-B) -cos(A+B)\\\\=2 + 2cos(A-B)\\\\=2(1 + cos(A-B))\\\\=2\times 2 cos^2(\frac{A-B}{2})\\\\=4cos^2(\frac{A-B}{2})[/tex]

Hence proved .


Related Questions

What is the volume of this cube?

Answers

Answer:

1 cubic ft

Step-by-step explanation:

Volume = Length × width × height

= 1 × 1 × 1

= 1

Answer:

1 cubic ft

Step-by-step explanation:

Volume = l × w × h

= 1 × 1 × 1

= 1 cubic ft

How many students were questioned about the approximate number of text messages they send each day? Explain or

show how you arrived at your answer.

Answers

Do you have anymore information that doesn’t help that much

g A radio station’s poll found that 68% of the respondents in a random sample of listeners plan to see a live music show in the next month. A 95% confidence interval for the population proportion was 0.68 ± 0.04. What is the correct interpretation of the 95% confidence interval? We can be 95% confident that 68% of all listeners will see a live music show in the next month. There is a 95% probability that between 64% and 72% of the listeners will see a live music show in the next month. There is a 5% chance that less than 64% or more than 72% of listeners will see a live music show in the next month. We can be 95% confident that the true proportion of listeners who will see a live music show in the next month is between 64% and 72%. If we repeatedly took samples of the same size from listeners of this radio station, approximately 95% of those samples would have between 64% and 72% of the sample going to see a live music show in the next month.

Answers

Answer:

We can be 95% confident that the true proportion of listeners who will see a live music show in the next month is between 64% and 72%.

Step-by-step explanation:

x% confidence interval:

A confidence interval is built from a sample, has bounds a and b, and has a confidence level of x%. It means that we are x% confident that the population mean is between a and b.

A 95% confidence interval for the population proportion was 0.68 ± 0.04.

We are 95% sure that the true population proportion is between 0.68 - 0.04 = 0.64 and 0.68 + 0.04 = 0.72.

Thus, the correct answer is:

We can be 95% confident that the true proportion of listeners who will see a live music show in the next month is between 64% and 72%.

Which of the following statements are true about solids shown above
Check all that apply
A prism a has a lateral surface are of 60 cm 2
B prism b has a total surface are of 110 cm 2
C prism b has larger surface area
D prisms A and B have different values for lateral surface area

Answers

Ans its b and c

Step-by-step explanation:

i need help badly due today

Answers

Answer:

Solid A

Step-by-step explanation:

4 more than a number is 12

Answers

Answer:

555

Step-by-step explanation:

Answer:

4 + x = 12

x = 8

Step-by-step explanation:

4 more than a number is 12

I will represent the mystery number as "x"

4 + x = 12

x = 8

Casey boards a Ferris wheel at the 3-o'clock position and rides the Ferris wheel for multiple revolutions. The Ferris wheel rotates at a constant angular speed of 5.6 radians per minute and has a radius of 50 feet. The center of the Ferris wheel is 55 feet above the ground. Let t represent the number of minutes since the Ferris wheel started rotating.
a. Write an expression (in terms of t) to represent the varying number of radians θ Ryan has swept out since the ride started.
b. Write an expression (in terms of t) to represent Ryan's height (in feet) above the ground.

Answers

Solution :

It is given that :

Casey boarded a Ferry wheel at position of 3 'o' clock.

The angular speed of the Ferry wheel = 5.6 radians per minute

The radius of the Ferry wheel = 50 feet

The height of the center wheel of the Ferry from the ground = 55 feet

Let the number of minutes be = t

a). The expression of the varying number of radians θ is given by :

After t minutes,  θ = angle swept

                           θ = 5.6 t radians

b). Finding the height from the center of the wheel.

We know that : y = r sin θ

Given r = 50 feet

So, y = 50 sin (5.6 t) feet

Therefore, the height above the ground can be found by :

h = y + 55 (from ground)

h = 50 sin (5.6 t) + 55   feet

Matthew decided to bake cupcakes for the school fundraiser. He wants to make 2 dozen cupcakes--one dozen strawberry and one dozen chocolate. He needs 2 1/4 cups of flour for the strawberry cupcakes and 2 1/3 cups of flour for the chocolate cupcakes, but he only has 4 cups of flour. Which two expressions could be used to correctly determine the amount of flour, in cups, Matthew still needs to bake his two dozen cupcakes? 2 part what is the total amount of flour, in cups, Mathew still needs for his cupcakes? NO LINK

Answers

Answer:

[tex]4+c=2\frac{1}{4}+2\frac{1}{3},\\\\\frac{7}{12}\:\text{more cups of flour}[/tex]

Step-by-step explanation:

The total amount of flour, in cups, Matthew needs is equal to [tex]2\frac{1}{4}+2\frac{1}{3}=4\frac{7}{12}[/tex]. Because he only has 4 cups, we can write the following expression to determine how many additional cups of flour he needs:

[tex]4+c=2\frac{1}{4}+2\frac{1}{3},\\\\4+c=\frac{7}{12}, \\\\c=\boxed{\frac{7}{12}\:\text{more cups of flour}}[/tex]

How do you write 6.00 × 10–5 in standard form?

Answers

Answer:

[tex]60x-5[/tex]

Step-by-step explanation:

Multiply 10 by 6

60x - 5

What is the volume of the given picture below? ( HELP PLEASE )

Answers

It's 904.78.

The formula for the volume of a sphere is 4/3(pi)r^3. The diameter is 12. Half it to get the radius, which is 6. Plug 6 into the formula. The result is 904.77868.

Find the volume. If you have any problems please tell me thank you.

Answers

Answer:

Step-by-step explanation:

Formula = V = l x w x h

V = 4.25 x 2.75 x 5

V = 58.438 --> 58.44

Help will be appreciated I need help with math

Answers

3. (-12,4)
4. (0,-14)
5. (14,0)
6. (0,0)

HELP!!!!

5^m x (5^-7)^m = 5^12

Answers

Answer:

not sure lol but, like it up

Step-by-step explanation:

common
factors of 10 and 20​

Answers

Answer:

Step-by-step explanation:

common factor of 10 and 20 is 2 and 10 because 2 and 10 are the numbers which didides both the number exactly.

What is the slope of a line that runs through (-2,4) and (3,7)

Answers

Answer: m=0.6

Step-by-step explanation:

Use the m= y2-y1/x2-x1 formula to calculate slope.

7-4=3

Divided by

3-(-2)=5

3/5= 3/5 or 0.6

Answer:

slope = 3/5

Step-by-step explanation:

slope  = rise/run

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

y rises from 4 to 7 = 3

x runs from -2 to 3 = 5

slope = 3/5

DO NOW
1)_Write an equation that represents the
line whose slope is 5 and has a (-2,4) on
the line.

Answers

Answer:

y=5x+14

Step-by-step explanation:

Plug this into the equation y-y1=m(x-x1) where m is the slope. y1 is equal to 4, x1 is equal to -2, and m is equal to 5. This will make the equation y-4=5(x--2). This is equal to y-4=5(x+2). Use the distributive property to get y-4=5(x)+5(2). Simplify to get y-4=5x+10. We want to isolate y so we have to add 4 to both sides. This will be equal to y=5x+10+4. Combine like terms to get y=5x+14. Therefore, the equation is y=5x+14.

If this helps please mark as brainliest

Evaluate 4x - y if x = 3 and y = 6

Answers

Answer:

The answer is 6

Step-by-step explanation:

4 (3) - 6

12 - 6

= 6.

hope this helps! feel free to clarify

If you rolled two dice, what is the probability
that you would roll a sum of 4?
Give your answer as a simplified fraction. Enter
the number that belongs in the green box.
3
second
first
1 2
4 5 6
11,1 1,2 1,3 1,4 1,5 1,6
22,1 2,2 2,3 2,4 2,5 2,6
33,1 3,2 3,3 3,4 3,5 3,6
4 4,1 4,2 4,3 4,4 4,5 4,6
55,1 5,2 5,3 5,4 5,5 5,6
6 6,1 6,2 6,3 6,4 6,5 6,6
Enter

Answers

Answer:

1/12

Step-by-step explanation:

3/36=1/12

) As an ice cube melts its surface area is decreasing at a rate of 6cm2/sec. Find the rate at which the length of each side is decreasing at the moment when each side has length 2 cm. [Hint: a cube has 6 sides and each side has area x 2 where x is the side length]

Answers

Answer:

The rate of decreasing of the length is 0.25 cm/s.

Step-by-step explanation:

The surface area of the ice cube is:

[tex]A_{ice}=6x^{2}[/tex]

Where x is the side of the cube.

Let's take the derivative of A with respect to "t" to get the rate of change.

[tex]\frac{dA_{ice}}{dt}=12x\frac{dx}{dt}[/tex]

We know that dA/dt = 6 cm²/s and x is 2 cm, so we just need to solve it for dx/dt which is the rate change of the length.

[tex]6=12(2)\frac{dx}{dt}[/tex]

[tex]\frac{dx}{dt}=\frac{1}{4}\: cm/s[/tex]

Therefore, the rate of decreasing of the length is 0.25 cm/s.

I hope it helps you!

Estimate the solution to the following system of equations by graphing. 3x + 5y = 14
6x - 4y = 9

Answers

Step-by-step explanation:

hope helps u

have a nice day


Chau rented a truck for one day. There was a base fee of $18.95, and there was an additional charge of 95 cents for each mile driven. Chau had to pay $198.50
when he returned the truck. For how many miles did he drive the truck?

Answers

Let's say John drove 2 miles. He had to pay the base fee of $18.99 and $.75(2) = $1.50, so he paid $20.49 total.

We are given his total, though, and asked to find the mileage.

18.99 + .75m = 199.74

-18.99 -18.99

.75m = 180.75

.75 .75

m = 241

So, John drove 241 miles.

Hope this helps!

I

a letter to PTA chairman about school problems ​

Answers

Answer:

Dear Chairman/or MR.?….

Re: Concerns regarding insanitary conditions/health of children

I would be grateful if you could let me have the latest Minutes of PTA Meetings particularly if they relate to the health of young people as it relates to the lack of proper cleaning and the general insanitary conditions in the toilets and areas where food is consumed by children

Whilst l am aware that schools are always short of cash for what may be regarded as non-essentials, l would like the opportunity to discuss with you my ideas on dealing with this very important aspect of basic hygiene, cleanliness and education if it is found to be that the insanitary conditions are such which young people themselves may be partly responsible. If funds are needed for the purchase of specific items l have suggestions as to the raising of funds for these.

I look forward to hearing from you as a matter of urgency.

Yours sincerely,

, if addressed by name/ faithfully, if not by name,

Step-by-step explanation:

whats the answer. ill make this 20 pts

Answers

Answer:

B

Step-by-step explanation:

[tex] \sqrt[y]{ {x}^{z} } = {x}^{ \frac{z}{y} } \\ [/tex]

If f(1)=6f(1)=6 and f(n)=nf(n-1)-4f(n)=nf(n−1)−4 then find the value of f(3)f(3).

Answers

Answer:

49

Step-by-step explanation:

Answer:6144

Step-by-step explanation:

If f(1)=6f(1)=6 and f(n)=4f(n-1)f(n)=4f(n−1) then find the value of f(6)f(6).

f(1)=

f(1)=

\,\,6

6

f(\color{darkgreen}{2})=

f(2)=

\,\,4f(\color{darkgreen}{2}-1)

4f(2−1)

=

=

\,\,4f(1)

4f(1)

=

=

\,\,4(6)

4(6)

Substitute f(1)=6

f(2)=

f(2)=

\,\,24

24

f(\color{darkgreen}{3})=

f(3)=

\,\,4f(\color{darkgreen}{3}-1)

4f(3−1)

=

=

\,\,4f(2)

4f(2)

=

=

\,\,4(24)

4(24)

Substitute f(2)=24

f(3)=

f(3)=

\,\,96

96

f(\color{darkgreen}{4})=

f(4)=

\,\,4f(\color{darkgreen}{4}-1)

4f(4−1)

=

=

\,\,4f(3)

4f(3)

=

=

\,\,4(96)

4(96)

Substitute f(3)=96

f(4)=

f(4)=

\,\,384

384

f(\color{darkgreen}{5})=

f(5)=

\,\,4f(\color{darkgreen}{5}-1)

4f(5−1)

=

=

\,\,4f(4)

4f(4)

=

=

\,\,4(384)

4(384)

Substitute f(4)=384

f(5)=

f(5)=

\,\,1536

1536

f(\color{darkgreen}{6})=

f(6)=

\,\,4f(\color{darkgreen}{6}-1)

4f(6−1)

=

=

\,\,4f(5)

4f(5)

=

=

\,\,4(1536)

4(1536)

Substitute f(5)=1536

f(6)=

f(6)=

\,\,6144

6144

\text{Geometric Sequence:}

Geometric Sequence:

Common ratio of 4

6,24,96,384,1536,6144, ...

6,24,96,384,1536,6144,...

\text{Final Answer:}

Final Answer:

6144

pls help!! correct answer will be marked brainliest

Answers

Answer:

67.7

Step-by-step explanation:

Because it is the exact same as 67.7 angle n is. So it is 67.7 I went over this recently so I understand your pain!

at what rate percent of interest per annum will #700 gain an interest of #84 in 3 years​

Answers

Answer:

4% per annum

Step-by-step explanation:

Recall :

Simple interest = principal * rate * time

Given that :

Time = 3 ; simple interest = 84 ; principal = 700

84 = 700 * rate * 3

84 = 2100 * rate

Rate = 84 /2100

= 0.04

= 0.04 * 100% = 4% per annum

if f(x)= 9+3x, find f(-2)

Answers

Answer:

f(-2) =3

Step-by-step explanation:

f(x) = 9+3x

Let x=-2

f(-2) = 9+3(-2)

      = 9-6

      = 3

f ( -2 ) = 9 + 3( - 2 )

f ( -2 ) = 9 - 6

f ( -2 ) = 3

Can someone help me please?

Answers

Answer:

.08

Step-by-step explanation:

Answer:

Hi, there your answer is 0.08

Step-by-step explanation:

What is the shape of the base of the cylinder?

Answers

Answer:

circle

Step-by-step explanation:

circle because the bottom of a cylinder is circle it’s kinda common sense lol

find the ratio of volumes of two cuboids whose sides are in the ratio 3/1

Answers

Answer:

The ratio of volumes is of 27.

Step-by-step explanation:

Volume of a cuboid:

A cuboid has dimensions length l, width w and height h. The volume is given by:

[tex]V = lwh[/tex]

Multiplying dimensions by 3:

This means that l = 3l, w = 3w, h = 3h. So

[tex]V_m = 3l(3w)(3h) = 3*3*3*lwh = 27lwh[/tex]

Ratio of volumes:

[tex]\frac{V_m}{V} = \frac{27lwh}{lwh} = 27[/tex]

The ratio of volumes is of 27.

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