(cos2a-cos2b)² + (sin2a+sin2b)²=4sin²(a+b)​

Answers

Answer 1

Answer:

LHS = (cosA+cosB)²+(sinA+sinB)²

= (cos²A+2cosAcosB+cos²B)+

(sin²A+2sinAsinB+sin²B)

/* By algebraic identity:

(x+y)² = x²+2xy+y² */

Rearranging the terms, we get

= (cos²A+sin²A)+(cos²B+sin²B)+2(cosAcosB+sinAsinB)

= 1+1+2cos(A-B)

________________________

we know that,

i) cos²x + sin²x = 1

ii) cosxcosy+sinxsiny = sin(x-y)

________________________

= 2+2cos(A-B)

= 2[1+cos(A-B)]

\boxed {1+cos\theta = 2cos^{2}\frac{\theta}{2}}

1+cosθ=2cos

2

2

θ

= 2\times 2cos^{2}\frac{(A-B)}{2}2×2cos

2

2

(A−B)

=4cos^{2}\frac{(A-B)}{2}4cos

2

2

(A−B)

=RHSRHS

Therefore,

(cosA+cosB)²+(sinA+sinB)²

=4cos^{2}\frac{(A-B)}{2}4cos

2

2

(A−B)


Related Questions

42 deliveries in 3 hours = deliveries per hour

Answers

Answer:

14 deliveries per hour

Step-by-step explanation:

42/3

14

The person makes 14 deliveries per hour

Answer:

14

Step-by-step explanation:

42 / 3 = 14

Find the cross product (7,9, 6)x 44, 1, 5). Is the resulting vector perpendicular to the given vectors?
a. (-57, 43, 33); yes
c. (33. – 59, - 57); no
b. (39, – 59,43), yes
d. (33, - 57, 49); no

Answers

Answer:

Option B, (39, -59, 43)

Answered by GAUTHMATH

You would like to know how effective a diet program is at helping people lose weight. 18 over-weight people are randomly selected to participate in the program. They are weighed before and after the program and the results are listed below. Do these results give evidence that the diet program is effective at the 1% significance level?

Answers

Answer:

There is not enough evidence to support the claim that drug is effective at 1%

Step-by-step explanation:

For this we use the pored test as we have dependent test;

Difference :

10,5,-5,3,-3,4,2,-3,0,10,8,-2,3,-2,5,5,4,0

Hypothesis :

H0 : μd = 0

H0 : μd ≠ 0

The mean of d, dbar = Σd / n = 44 / 18 = 2.44

The standard deviation, Sd = 4.45 (using calculator)

The test statistic, T : dbar / (Sd/√n)

T = 2.44 / (4.45/√18)

T = 2.44 / 1.0488750

T = 2.326

Degree of freedom, df = n - 1 ; 18 - 1 = 17

The Pvalue = 0.0326

α = 0.01

Since Pvalue < α ; we fail to reject H0

if measure of three angles of a quadrilateral are 65 degree 95 degree and 45 degree then find the measure of the fourth​ angle?

Answers

Answer:

155 degrees

Step-by-step explanation:

Hi there!

The sum of the interior angles of a quadrilateral is always 360 degrees. To find the measure of the fourth angle, subtract 65, 95 and 45 from 360:

360-65-95-45

= 155

Therefore, the measure of the fourth angle is 155 degrees.

I hope this helps!

Answer:

155 degrees

Step-by-step explanation:

A quadrilateral has a total internal angle sum of 360 so we can set up an equation where x is the fourth angle

360=65+95+45+x

360=205+x

x=155


Four times an angle is equal to half of its supplement. Find the measures of both angles.

Answers

Answer:

The bigger angle is 144 degrees and the smaller one is 36 degrees

0.4 x 10 =....
1.25 x 10 =
97.465 x10 =​

Answers

Answer:

0.4 × 10 = 4

1.25 × 10 = 12.5

97.465 × 10 = 974.65

Find the place value of 8 in 2456.1387.
Tenths
Hundredths
Thousandths
Thousands

Answers

Answer: Third Choice. Thousandths

Step-by-step explanation:

Concept:

Here, we need to know the order and name of each place value.

Please refer to the attachment below for the specified names.

Solve:

STEP ONE: Orde and name each place

2 ⇒ One Thousands

4 ⇒ Hundreds

5 ⇒ Tens

6 ⇒ Ones

.

1 ⇒ Tenths

3 ⇒ Hundredths

8 ⇒ One Thousandths

7 ⇒ Ten Thousandths

STEP TWO: Find the number [8] in the number

As we can see from the list above, 8 is at the right of the decimal point, thus, the place value is Thousandths.

Hope this helps!! :)

Please let me know if you have any questions

A retailer bought 1000 glass tumblers at rs 80 each.50 glass tumblers were broken and he sold the rest at Rs 96 each .find his profit or loss percent​

Answers

Step-by-step explanation:

Soln

Given

Cp of 1 glass tumbler=80.1000

=Rs 80000

Number of broken glass tumbler=50

Number of remaining glass tumbler=1000-50

=950

Sp of one glass tumbler=96

Sp of 950 glass tumbler=96.950

=91200

Now

Sp > Cp so it is profit

Profit%=sp-cp/cp.100

=91200-80000/80000.100

=11200/80000.100

=14%

Answer:

14%profit

Step-by-step explanation:

Cost of 1000 tumblers=1000×80=80,000

50 of them were broken: 1000-50=950

: He sells 950 tumblers of rs.96 each= ( 950×96)

S.P=91200

We can clearly see he gains for rs.11200.

P%=gain/C.P×100

11200×80000×100

=14%

(Picture) Could someone help me solve this I need to use Inverse Operations but I don't fully understand? I'll mark brainliest, 10 Points.

Answers

Answer:

[tex]x = - 8[/tex]

Step-by-step explanation:

First,Step write the given equation.

[tex] \frac{x}{2} + 7 = 3[/tex]

In Algebra, we learn how to solve for a missing term called a variable. We must use inverse operations to undo terms to isolate our variable. Inverse operations means that we do the opposite of the given.

Opposite of Addition is Subtraction, vice versa.Opposite of Multipication is Division, vice versa.

For example, say we have a equation

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

We would subtract 2 from both sides. E.g( remember the golden rule of algebra). What we do to one side, we do the other. This applies when we solving for a variable.

This means that

[tex]x = 1[/tex]

And if we substitute 1 in for x, it is indeed true.

[tex]1 + 2 = 3 = 3[/tex]

Now, back to the question.

[tex] \frac{x}{2} + 7 = 3[/tex]

First, we subtract 7 from both sides to get rid of the 7 on the left side. Also remeber to undo terms that aren't included in the variable when solving these problems.

So now we got

[tex] \frac{x}{2} = - 4[/tex]

Then we multiply 2 by both sides since that the opposite of division.

[tex] \frac{x}{2} \times 2 = x = -4 \times 2 = - 8[/tex]

So this means that

[tex]x = - 8[/tex]

If we plug this in, this is true.

[tex] \frac{ - 8}{2} + 7 = 3[/tex]

You flip a coin and roll a six-sided die. What is the
probability of flipping heads and rolling a number greater
than or equal to 5?

Answers

Answer:

The probability of flipping heads is 1/2

The probability of rolling 5 or more is 1/3.

So the total probability is 1/2 x 1/3 , which is 1/6.

Let me know if this helps!

Answer:

1/6

Step-by-step explanation:

The probability of flipping heads is 1/2

The probability of rolling 5 or more is 1/3.

So the total probability is 1/2 x 1/3 , which is 1/6.

any 5
algebraic formulas

Answers

Answer:

a2 – b2 = (a – b)(a + b)

(a + b)2 = a2 + 2ab + b2

a2 + b2 = (a + b)2 – 2ab

(a – b)2 = a2 – 2ab + b2

(a + b + c)2 = a2 + b2 + c2 + 2ab + 2bc + 2ca

(a – b – c)2 = a2 + b2 + c2 – 2ab + 2bc – 2ca

(a + b)3 = a3 + 3a2b + 3ab2 + b3 ; (a + b)3 = a3 + b3 + 3ab(a + b)

(a – b)3 = a3 – 3a2b + 3ab2 – b3 = a3 – b3 – 3ab(a – b)

a3 – b3 = (a – b)(a2 + ab + b2)

a3 + b3 = (a + b)(a2 – ab + b2)

(a + b)4 = a4 + 4a3b + 6a2b2 + 4ab3 + b4

(a – b)4 = a4 – 4a3b + 6a2b2 – 4ab3 + b4

a4 – b4 = (a – b)(a + b)(a2 + b2)

a5 – b5 = (a – b)(a4 + a3b + a2b2 + ab3 + b4

Answer:

a2 – b2 = (a – b)(a + b)

(a + b)2 = a2 + 2ab + b2

a2 + b2 = (a + b)2 – 2ab

(a – b)2 = a2 – 2ab + b2

(a + b + c)2 = a2 + b2 + c2 + 2ab + 2bc + 2ca

(a – b – c)2 = a2 + b2 + c2 – 2ab + 2bc – 2ca

(a + b)3 = a3 + 3a2b + 3ab2 + b3 ; (a + b)3 = a3 + b3 + 3ab(a + b)

(a – b)3 = a3 – 3a2b + 3ab2 – b3 = a3 – b3 – 3ab(a – b)

a3 – b3 = (a – b)(a2 + ab + b2)

a3 + b3 = (a + b)(a2 – ab + b2)

(a + b)4 = a4 + 4a3b + 6a2b2 + 4ab3 + b4

(a – b)4 = a4 – 4a3b + 6a2b2 – 4ab3 + b4

a4 – b4 = (a – b)(a + b)(a2 + b2)

a5 – b5 = (a – b)(a4 + a3b + a2b2 + ab3 + b4)

Which graph represents the function? f(x)=5√x

Answers

Step-by-step explanation:

Since the x is inside of the square root, the x value must be positive. This makes x {0,infinity). Yet, when square rooting x, you should have both a negative and a positive value for y. So, this should be your graph.

on the number line, which of the following numbers below can be found on the right of 2.26??
A.2.30
B.-2.25
C.2.25
D.1.26​

Answers

Answer:

2.25

Step-by-step explanation:

The lower number will always be on the right side unless its negative numbers , So the lower number is 2.25 , Why it isn't 1.26 is because its much far from 2.26 and so cannot be counted . Thanks

Courtney needs to wrap this gift box, which is 412 inches wide, 6 inches long, and 3 inches tall. What is the surface area of the box?

Answers

There is the answer. To get surface area you have to get all the surfaces first

If 1 angle is four time of another angle in linear pair find the angles. Please do it fast as you can

Answers

Answer:

let the angle be x then other angle is 4x

so,

x + 4x = 180

5x = 180

x = 36

so other angle I.e 4x = 4 × 36 = 144

Let one angle be x

Other angle=4x

Both are linear pair hence their sum will be 180

[tex]\\ \sf \longmapsto x+4x=180[/tex]

[tex]\\ \sf \longmapsto 5x=180[/tex]

[tex]\\ \sf \longmapsto x=\dfrac{180}{5}[/tex]

[tex]\\ \sf \longmapsto x=30[/tex]

[tex]\\ \sf \longmapsto 5x=5(30)=150[/tex]

Single adults: According to a Pew Research Center analysis of census data, in 2012, 20% of American adults ages 25 and older had never been married. Suppose that we select random samples from this population of American adults ages 25 and older. For each sample we then calculate the proportion that had never been married.

For which of the following sample sizes will the sampling distribution be approximately normal?

Wang, W., and Parker, K. (2014). Record Share of Americans Have Never Been Married. Pew Research Center. http://www.pewsocialtrends.org/2014/09/24/record-share-of-americans-have-never-married/

A) 25
B) 50
C) 75

Answers

Answer:

B. 50

Step-by-step explanation:

Central limit theorem is used to calculate the sampling distribution of the given case. The number of adults who are 25 years of age or above and not married is 20% of the samples selected. The standard deviation is 0.06 while the sample size should be 50 to conclude the results.

will mark brainliest help!

In parallelogram ABCD, m∠B = 105°.

What is the value of x. (Round your answer to the nearest tenth, if necessary.)

Answers

Answer:

52.5

Step-by-step explanation:

Since ED ≈ AD, ∆AED is a isosceles triangle where <EAD and <AED has same angle measurement

Now, m<B = 105°, since ABCD is a parallelogram, <B = <D

so, m<ADC = 105° so, m<ADE = 180°-105° = 75°

Now, m<EAD+m<AED+m<ADE = 180°

or, m<AED+m<AED+m<ADE = 180°

or, x+x+75°=180°

or, 2x=180+75°

or, 2x=105°

or, x=52.5°

name the property that the following statement illustrates 84+8=8+84

Answers

Answer:

the commutative property of addition :)

factorize = n!+(n-1)!

Answers

Answer:

Hello,

Step-by-step explanation:

n! + (n-1)!

=(n-1)! * n+ (n-1)!

=(n-1)! * (n+1)

evaluate the expression. check all possible sets that the solution may belong in. 40-5^2

Answers

Answer:

15

Step-by-step explanation:

following PEMDAS, we don't have () so we move on to exponents

5^2 is equal to 5 x 5 which is 25

40-25=15

[tex]\huge\textsf{Hey there!}[/tex]

[tex]\large\textsf{40 - 5}\mathsf{^2}\\\\\\\large\textsf{5}\mathsf{^2}\\\large\textsf{= 5}\times\large\textsf{5}\\\large\textsf{= \bf 25}\\\\\\\large\textsf{= 40 - 25}\\\\\\\large\textsf{= \bf 15}\\\\\\\\\\\\\boxed{\boxed{\huge\textsf{Therefore your answer is: \bf 15}}}\huge\checkmark[/tex]

[tex]\huge\textsf{Good luck on your assignment \& enjoy your day!}[/tex]

~[tex]\textsf{Amphitrite1040:)}[/tex]

1. The product of two consecutive numbers is 42. What are the numbers?

Answers

Answer:

6, 7

Step-by-step explanation:

6 x 7 = 42

6 and 7 are consecutive
6*7=42

2-6=? need help please

Answers

the answer is -4 hope that helps :)
Answer:

The answer is -4

Step-by-step explanation:

2 - 6 = -4

Given the function g(x) = x2 + 10x + 18, determine the average rate of change of
the function over the interval -11 < x < -1.

Answers

Answer:

-2.

Step-by-step explanation:

Average rate of change of the function = [ f(-1) - f(-11)] / [(-1 - (-11)]

= [(-1)^2 + 10*-1 + 18 - ((-11)^2 + 10*-11 + 18)] / 10

= (1 - 10 + 18 - (121 - 110 + 18) / 10

= (9 - (29) /10

= -20/10

= -2.

Answer:

Step-by-step explanation:

The answer is +2 or 2.

An item is regularly priced at $95. It is on sale for 85% off the regular price.

Answers

Answer:

14.25

Step-by-step explanation:

95*0.85=80.75

95-80.75=14.25

Answer:

The sale took $14.25 off the original price, so the item is currently $80.75 with the sale.

Samuel takes 5 hours to make a table and a chair. He takes 9 hours to make 3 chairs
and a table. How much time does he take to make a table?

Answers

Answer:

3 hours

Step-by-step explanation:

t = time to make a table

c = time to make a chair

t + c = 5

t+3c = 9

Subtract the second equation from the first

t+3c = 9

-(t + c = 5)

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

       2c = 4

Divide by 2

2c/2 = 4/2

c =2

2 hours for the chair

t+c = 5

t+2 = 5

t = 5-2

t = 3hours

Answer:

It takes 3 hours to make a table.

Step-by-step explanation:

Table and chair : 5 hours

Table and 3 chairs : 9 hours

(Table and 3 chairs) - (Table and chair) = (2 chairs)

9 hours - 5 hours = 4 hours

2 chairs : 4 hours / 1 chair : 2 hours

Table and chair : 5 hours

Chair : 2 hours

Table: x hours

5 - 2 = 3

Table : 3 hours

Someone please help me find y if you don’t mind Thankyouu so much

Answers

Answer:

Step-by-step explanation:

Decreasing rate = 12% = 0.12

y = 2400 * (1- 0.12)^x = 2400*(0.88)^x

x = 8 years

[tex]y = 2400 *(0.88)^{8}\\\\= 2400*0.36\\\\= 863[/tex]

PLS HELP ME ON THIS QUESTION I WILL MARK YOU AS BRAINLIEST IF YOU KNOW THE ANSWER!!
The _____________ may be the average of 2 values in a data set.
A. range
B. interquartile range
C. mode
D. median

Answers

Answer:

as per my nowledge ans wud be b

as A means difference of highest and lowest

C means value appearing frequently

D means middle number or ascending or descending sequence

beainliest plz

Answer:

b

i dont want brainlist

Step-by-step explanation:

Do you think mathematics is used when collecting and reporting your data ? Give your reasons.

Answers

yes because everyone needs mathematics

mathematics are everywhere even if u said u dont like math u still cant get away with math

Look at this cube
If the side lengths are halved, then which of the following statements about its surface area will be true?

Answers

Answer:

the new surface Will be 1/4 pf the old surface

Step-by-step explanation:

because the surface with 7 in Is about 294 and with 3.5 (1/2 of 7) Is 73.5.

so 294:4 Is 73.5

excuse me for my bad English but I'm italian

The difference of a number and 11

Answers

Answer:

x - 11

Step-by-step explanation:

"A number" is the same thing as a variable.

Answer:

x-11

Step-by-step explanation:

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