a. 8
b. 4
c. 16
d. 12

It looks like your equation (it's not an identity) is

2 cos(5x) cos(3x) + sin(x) = cos(8x)

Recall that

cos(x + y) = cos(x) cos(y) - sin(x) sin(y)

cos(x - y) = cos(x) cos(y) + sin(x) sin(y)

==>   2 cos(x) cos(y) = cos(x + y) + cos(x - y)

so that

2 cos(5x) cos(3x) = cos(8x) + cos(2x)

Then the equation simplifies to

cos(8x) + cos(2x) + sin(x) = cos(8x)

cos(2x) + sin(x) = 0

Also recall that

cos(2x) = 1 - 2 sin²(x)

so the equation is quadratic in sin(x) and can be factorized:

1 - 2 sin²(x) + sin(x) = 0

2 sin²(x) - sin(x) - 1 = 0

(2 sin(x) + 1) (sin(x) - 1) = 0

Solve for x :

2 sin(x) + 1 = 0   or   sin(x) - 1 = 0

sin(x) = -1/2   or   sin(x) = 1

[x = arcsin(-1/2) + 2nπ   or   x = π - arcsin(-1/2) + 2nπ]   or   x = arcsin(1) + 2nπ

(where n is any integer)

x = -π/6 + 2nπ   or   x = -5π/6 + 2nπ   or   x = π/2 + 2nπ

Answer:

-12 =x

Step-by-step explanation:

5 [(x/6)-2] = 2x + 4

Distribute

5/6x - 10 = 2x+4

Subtract 5/6x from each side

5/6x -10 -5/6x = 2x -5/6x +4

-10 =2x -5/6x +4

Subtract 4 from each side

-10-4 = 2x - 5/6x

Get a common denominator for the right side

-14 = 12/6x - 5/6x

-14 = 7/6x

Multiply each side by 6/7

-14 * 6/7 = 7/6 x * 6/7

-12 =x

Answer:

x = -12

Step-by-step explanation

Answer:

0.28

Step-by-step explanation:

[tex] \large\begin{gathered} {\underline{\boxed{ \rm {\red{Volume \: of \: Cone \: = \: \pi \: {r}^{2} \: \frac{h}{3} }}}}}\end{gathered}[/tex]

‌ ⇛76/2 = 38

‌ ⇛radius = 38 cm

[tex]\bf \Large \longrightarrow \:π \: × \: (38 \: cm)² \: × \: \frac{90 }{3} [/tex]

[tex]\bf \Large \longrightarrow \: \pi \: \times \: \:1444 \: {cm}^{2} \: \times \: \cancel\frac{90}{3} \: \: ^{30 \: cm} [/tex]

Option ( B ) is the correct answer

Answer:

y=-1

Step-by-step explanation:

As the line is horizontal in nature and pass through (2,-1), the equation is y=-1

Answer:

390 degrees

Step-by-step explanation:

The conversion factor is 180/pi

13 pi /6 * 180/pi

13/6 *180

390

Answer:

sqrt(2)

Step-by-step explanation:

Since this is a right triangle, we can use trig functions

sin theta = opp / hyp

sin 45 = x/2

2 sin 45 =x

2 (sqrt(2)/2) =x

sqrt(2) =x

Answer:

$3.00

Step-by-step explanation:

First find the markup

2.00 * 50%

2 * .5

1

Add this to the original price

2+1 =3

The store sells the cereal for $3.00

Answer:

$3

Step-by-step explanation:

The grocery store pays $2.00 for each box of cereal bought.

First, find 50% of the cost of each box:

2.00 x 0.50 = 1.00

Next, add the additional amount to the starting price:

2.00 + 1.00 = $3.00

$3.00 is your answer.

~

Answer:

2 + 5p

Step-by-step explanation:

Hi there!

Let [tex]p[/tex] equal the number of points scored by the red team.

We're given:

The blue team scored two more than five times the number of points scored by the red team.

⇒ blue team points = 2 + (5 × red team points)

⇒ blue team points = 2 + 5p

I hope this helps!

Answer:

See attached image for the sum computed using wolfram alpha, raw value is: 49382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382716049382715160

Answer:

Step-by-step explanation:

First, i divide all terms by 4

sequence is 1,11,111,1111,....,1111...1111 (with 2000 digits)

[tex]u_1=1\\\\u_2=11=10+1=\dfrac{10^2-1}{9}\\\\u_3=111=100+10+1=\dfrac{10^3-1}{9}\\\\u_4=1111=1000+100+10+1=\dfrac{10^4-1}{9}\\....\\u_n=\dfrac{10^n-1}{9}\\\\\\\displaystyle \sum_{i=1}^n\ u_1 =\dfrac{10^1-1}{9}+\dfrac{10^2-1}{9}+\dfrac{10^3-1}{9}+...+\dfrac{10^n-1}{9}\\=\dfrac{1}{9} *(10+10^2+10^3+....+10^n+1-1-(1+1+1+1...+1)\ )\\\\=\dfrac{1}{9}*( \frac{10^{n+1}-1}{9} -(n+1)\ )[/tex]

[tex]\boxed{4+44+444+....+444...4=\dfrac{4}{9}*( \dfrac{10^{2001}-1}{9} -2001\ )}\\\\\\\approx{4,9382716049382716049382716049383*10^{1999} }[/tex]

[tex]\\ \bull\sf\longmapsto -9+(-4)=-9-4=-13[/tex]

[tex]\\ \bull\sf\longmapsto +3-(-5)=3+5=8[/tex]

[tex]\\ \bull\sf\longmapsto 2\times 2=4[/tex]

[tex]\\ \bull\sf\longmapsto 36+4=40[/tex]

[tex]\\ \bull\sf\longmapsto 5\times 7=35[/tex]

[tex]\\ \bull\sf\longmapsto 8(9)=72[/tex]

[tex]\\ \bull\sf\longmapsto -4+(-2)=-4-2=-6[/tex]

[tex]\\ \bull\sf\longmapsto 3-(-6)=3+6=9[/tex]

[tex]\\ \bull\sf\longmapsto -6(-3)=18[/tex]

[tex]\\ \bull\sf\longmapsto -4+(-4)=-4-4=-8[/tex]

[tex]\\ \bull\sf\longmapsto 5(7)=35[/tex]

[tex]\\ \bull\sf\longmapsto 4-(-5)=4+5=9[/tex]

[tex]\\ \bull\sf\longmapsto 4-3=1[/tex]

[tex]\\ \bull\sf\longmapsto 10+5=15[/tex]

[tex]\\ \bull\sf\longmapsto 3(8)=24[/tex]

Answer:

Weak negative correlation

Answer:

9) 10

10) 5

Step-by-step explanation:

Answer:

C= 100+ d*0.2

Step-by-step explanation:

Give data

Cost of rental = $100

Cost per km= $0.2

Total cost= C

Distance= d

Let us model the expression

Hence the expression is given as

C= 100+ d*0.2

Answer:

B

Step-by-step explanation:

this is just common sense. if you would have tried you could have easily answered this yourself.

the sequence starts with 6. that is a1.

so, the formula simply has to add "something" to 6.

therefore, A and D are out.

and then we see immediately that the sequence is built by subtracting 4 (or adding -4) for every step.

so, we need to add multiples of -4.

therefore, only B is correct (C adds multiples of +4).

Answer:

Irrational

Step-by-step explanation:

If we evaluate the square root, we realize that the number will not be a perfect square.

Since it is not a perfect square, it will be an unending, never-repeating, decimal.

Therefore, it will be irrational.

Answer:

-15

Step-by-step explanation:

df(x, y) / dy = lim (f(x, y+h) - f(x, y)) / h =

lim (e^x^2 - 15y - 15h - e^x^2 ‐ 15y) / h = lim -15h / h = -15

so, the first derivative of f(x,y) by y is simply a constant : -15

fy (x, y) = -15 for any and every values of x and y.

the fast track would be derivative calculation :

the derivative by y makes x a constant. and every constant is eliminated for derivation.

so, e^x^2 goes away (= 0 in the derivative).

that leaves -15y = -15×y¹. its derivative simply is

1×-15×y⁰ = -15

Answer:

The two functions have the same initial value

Answer:

133.33

Step-by-step explanation:

Answer:

133 1/3 or 133.33

Step-by-step explanation:

So first let's turn 15% into a decimal. For me personally, its less intimidating that way.

15%=0.15

now, let's say the number we are trying to find is x.

A trick I use for these questions is to look at the words. "Of" is used when something is multiplied. "Is" is used for equal signs. So if 20 is 0.15 of x, our formula is easy to figure out!

20=0.15x

x=133.33333...

x=133 1/3

Answer:

5m^2-2m

Step-by-step explanation:

2m^2-2m + 3m^2

5m^2-2m

Answer:

5m² - 2m

Step-by-step explanation:

Given

2m² - 2m + 3m² ← collect like terms

= (2m² + 3m²) - 2m

= 5m² - 2m

Answer:

(1, - 2 )

Step-by-step explanation:

Given the equations

3x - 4y = 11 → (1)

y + 3x = 1 ( subtract 3x from both sides )

y = 1 - 3x → (2)

Substitute y = 1 - 3x into (1)

3x - 4(1 - 3x) = 11 ( distribute and simplify left side )

3x - 4 + 12x = 11

15x - 4 = 11 ( add 4 to both sides )

15x = 15 ( divide both sides by 15 )

x = 1

Substitute x = 1 into (2) for corresponding value of y

y = 1 - 3(1) = 1 - 3 = - 2

solution is (1, - 2 )

Answer:

D is the correct answer.

Answer:

1) 11[tex]\sqrt{3}[/tex]

2) 2[tex]\sqrt{2}[/tex]

3) [tex]20\sqrt{3} + 15\sqrt{2}[/tex]

4) [tex]53 + 12\sqrt{10}[/tex]

5) -2

6) [tex]7\sqrt{2} - 5\sqrt{3}[/tex]

Step-by-step explanation:

1) 2[tex]\sqrt{12}[/tex] + 3[tex]\sqrt{48}[/tex] - [tex]\sqrt{75}[/tex]

=(2 × 2[tex]\sqrt{3}[/tex] )+ (3 × 4[tex]\sqrt{3}[/tex]) - 5[tex]\sqrt{3}[/tex]

= 4[tex]\sqrt{3}[/tex] + 12[tex]\sqrt{3}[/tex] - 5[tex]\sqrt{3}[/tex]

= 11[tex]\sqrt{3}[/tex]

2) 4[tex]\sqrt{8}[/tex] -2[tex]\sqrt{98}[/tex] + [tex]\sqrt{128}[/tex]

= (4 × 2[tex]\sqrt{2}[/tex]) - (2 × 7[tex]\sqrt{2}[/tex]) + 8[tex]\sqrt{2}[/tex]

= 8[tex]\sqrt{2}[/tex] - 14[tex]\sqrt{2}[/tex] +8[tex]\sqrt{2}[/tex]

= 2[tex]\sqrt{2}[/tex]

3) 5[tex]\sqrt{12\\}[/tex] - 3[tex]\sqrt{18} + 4 \sqrt{72} +2\sqrt{75}[/tex]

= 5× [tex]2\sqrt{3}[/tex] - 3×[tex]3\sqrt{2}[/tex] + 4×[tex]6\sqrt{2}[/tex] + 2×[tex]5\sqrt{3}[/tex]

= [tex]10\sqrt{3} - 9\sqrt{2} +24\sqrt{2} +10\sqrt{3}[/tex]

= [tex]20\sqrt{3} + 15\sqrt{2}[/tex]

4) [tex](2\sqrt{2} + 3\sqrt{5} )^{2}[/tex]

= [tex]8 + 12\sqrt{10} + 45[/tex]

= [tex]53 + 12\sqrt{10}[/tex]

5) [tex](1+\sqrt{3} ) (1-\sqrt{3} )[/tex]

= [tex]1 - 3[/tex]

= -2

6) [tex](2\sqrt{6} -1) (\sqrt{3} -\sqrt{2} )[/tex]

= [tex]2\sqrt{18}-2\sqrt{12} -\sqrt{3} +\sqrt{2}[/tex]

= 2×[tex]3\sqrt{2}[/tex] - 2×[tex]2\sqrt{3}[/tex] - [tex]\sqrt{3} + \sqrt{2}[/tex]

= [tex]6\sqrt{2} - 4\sqrt{3} -\sqrt{3} +\sqrt{2}[/tex]

= [tex]7\sqrt{2} - 5\sqrt{3}[/tex]

Hope the working out is clear and will help you. :)

Step-by-step explanation:

please I solved the question in the diagram above

Answer:

0.16666...

6/36

2/12

3/18

4/24

5/30

There's a lot of things.

Answer:

it's off topic but which grade are you in

Answer:

17.00 and 17,000.00

this is your answer to ur question

Answer:

A

Step-by-step explanation:

Let's say we need x pounds of one-dollar-a-pound coffee . The coffee must average out to 84 cents a pound, and the formula for average is

sum of cost of coffee / number of pounds of coffee, so we have

0.84 = total cost of coffee / (x+80) . The total cost of coffee can be found to be the sum of the cost of $1 coffee and 70 cent coffee, so we have

0.84 = (cost of $1 coffee + cost of 70 cent coffee) / (x+80)

The cost of $1 coffee can be found by adding $1 for each pound of one dollar coffee, or $1 * x. Similarly, the cost of 70 cent coffee is equal to 0.70 * 80, so we have

0.84 = (1*x+0.7*80)/(x+80)

0.84 = (x+56)/(x+80)

multiply both sides by (x+80) to remove a denominator

0.84(x+80) = x+56

0.84x + 67.2 = x+56

subtract both sides by 56 and 0.84x to isolate the x and its coefficients

11.2 = 0.16 x

divide both sides by 0.16 to isolate x

11.2/0.16 = x = 70

The number of pounds of a constituent in a mixture given the cost of the

mixture and the cost and mass of the other constituent can be calculated

by using an equation to model the system

The correct option for the number of pounds of one-dollar- pound coffee needed is option A

(A) 70 pounds

The procedure for arriving at the correct option is as follows:

The given parameters are;

The cost of the the coffee for which the mass in the mixture is to be determined = One-Dollar a pound = 100 ¢ a pound

The mass of the coffee 70¢ a pound coffee to be mixed = 80 pounds

The cost per pound of the mixture = 84 ¢ a pound

The required parameter;

The number of pounds of the one-dollar-a-pound (100 ¢ a pound) coffee in the mixture

Method:

Let x (pound) represent the number of pounds of the one-dollar-a-pound coffee in the mixture, we have;

Mass of mixture = Mass of the one-dollar-a-pound in the mixture, x + Mass of 70 ¢ a pound in the mixture, 80

∴ Mass of mixture in pounds = x + 80

Cost = Cost per pound × Number of pound

Find solution by applying the equation;

Cost of the constituents = Cost of the mixture

Where;

Cost of the constituents = $1 × x + 70 ¢ × 80 = 100 ¢ × x  + 70 ¢ × 80

Cost of the mixture = 84 ¢ × (x + 80)

Therefore;

100 ¢ × x  + 70 ¢ × 80 = 84 ¢ × (x + 80)

The above can be expressed as 100·x + 70×80 = 84 × (x + 80)

Expanding, evaluating and collecting like terms gives;

100·x + 5,600 = 84·x + 6,720

100·x - 84·x = 6,720 - 5,600 = 1,120

16·x = 1,120

x = 1,120/16 = 70

The number of pounds of one-dollar- pound coffee needed, x = 70 pounds

Learn more about equation modelling here;

https://brainly.com/question/14102741