prove the identity sin3x=3sinx-4sin³x

9514 1404 393

Answer:

Step-by-step explanation:

Let d and s represent the cost of a drink and a sandwich, respectively. The two purchases give rise to the equations ...

  3d +5s = 25.05

  4d +2s = 13.80

Dividing the second equation by 2 gives ...

  2d + s = 6.90

Subtracting the first equation from 5 times this, we get ...

  5(2d +s) -(3d +5s) = 5(6.90) -25.05

  7d = 34.50 -25.05 = 9.45

  d = 1.35

The cost of each drink is $1.35.

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Additional comment

Using the simplified 2nd equation, we can find the cost of a sandwich.

  s = 6.90 -2d = 6.90 -2.70 = 4.20

The cost of each sandwich is $4.20.

Answer:

See attachment for graph

Step-by-step explanation:

Given

[tex]f(x) = \left[\begin{array}{cc}-1&x<-1\\0&-1\le x \le -1\\1&x>1\end{array}\right[/tex]

Required

The graph of the step function

Before plotting the graph, it should be noted that:

[tex]\le[/tex] and [tex]\ge[/tex] use closed circle at its end

[tex]<[/tex] and [tex]>[/tex] use open circle at its end

So, we have:

[tex]f(x) = -1,\ \ \ \ x < -1[/tex]

The line stops at -1 with an open circle      

[tex]f(x) = 0,\ \ \ \ -1 \le x \le 1[/tex]

The line starts at - 1 and stops at -1 with a closed circle at both ends

[tex]f(x) = 1,\ \ \ \ x > 1[/tex]

The line starts at 1 with an open circle

The options are not complete, so I will plot the graph myself.

See attachment for graph

Answer:

Area of rectangle = 2H² - 5H

Step-by-step explanation:

Translating the word problem into an algebraic expression, we have;

Length =2H - 5

To write the algebraic expression to model the area of the rectangle;

Mathematically, the area of a rectangle is given by the formula;

Area of rectangle = L * H

Where;

Substituting the values into the formula, we have;

Area of rectangle = (2H - 5)*H

Area of rectangle = 2H² - 5H

Answer:

D.√85

Step-by-step explanation:

We can find the distance between two points using the distance between two points formula

Distance between two points formula:

d = √(x2 - x1)² + (y2 - y1)²

Where the x and y values are derived from the given points

We are given the two points (-2,7) and (7,9)

Using these points let's define the variables ( variables are x1, x2, y1, and y2)

Remember points are written as follows (x,y)

The x value of the first point is -2 so x1 = -2

The x value of the second point is 7 so x2 = 7

The y value of the first point is 7 so y1 = 7

The y value of the second point is 9 so y2 = 9

Now that we have defined each variable let's find the distance between the two points

We can do this by substituting the values into the formula

Formula: d = √(x2 - x1)² + (y2 - y1)²

Variables: x1 = -2, x2 = 7, y1 = 7, y2 = 9

Substitute values in formula

d = √(7 - (-2))² + (9 - 7)²

Evaluation:

The two negative signs cancel out on 7-(-2) and it changes to +7

d = √ (7+2)² + (9-7)²

Add 7+2 and subtract 9 and 7

d = √ (9)² + (2)²

Simplify exponents 9² = 81 and 2² = 4

We then have d = √ 81 + 4

Finally we add 81 and 4

We get that the distance between the two points is √85

Answer:

True negative numbers are considered as diseased individual. So, the true negative numbers will increase

Step-by-step explanation:

True negative numbers are considered as diseased individual. So, the true negative numbers will increase.

Answer:

a ⊥ y

Step-by-step explanation:

since b is parallel to a & perpendicular to y , line y will eventually cut across line a at a 90 degree angle as well

Answer:

a ⊥ y

Step-by-step explanation:

Look at the image given below.

9514 1404 393

Answer:

Step-by-step explanation:

Dilation about the origin multiplies each coordinate value by the dilation factor.

  A' = 2A = 2(-1, -2) = (-2, -4)

  B' = 2B = 2(-1, 3) = (-2, 6)

 C' = 2C = 2(4, 3) = (8, 6)

  D' = 2D = 2(4, -2) = (8, -4)

Answer: Therefore 100 student tickets were sold

Step-by-step explanation:

Let the number of student tickets be x

So adult tickets = 390 - x

ATQ

4.5(x) + 6(390-x) = 2190

4.5x + 2340 - 6x = 2190

-1.5x + 2340 = 2190

-1.5x = 2190-2340

-1.5x = -150

x = -150/-1.5

x = 100

Therefore 100 student tickets were sold

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Answer:3 and 4

Step-by-step explanation:

Answer:

9/12 or 2/3

Step-by-step explanation:

Make both fractions have the same denominator by finding their least common multiple

1x12 = 12                1x3 = 3

2x6 = 12                3x1 = 3

3x4 = 12

4x3 = 12

6x2 = 12

12x1 = 12

In which case it would be 12.

1/3 would be 4/12

5/12 + 4/12 = 9/12

which is also 2/3 if your teacher wants the simplest answer

Answer:

The parent cubic function has been vertically stretched by a factor of 4.

Equation:G(x)= 4[tex]\sqrt[3]{x}[/tex]

Answer: Option B

OAmalOHopeO

Answer: x + y = 180²

Step-by-step explanation:

A linear pair is a pair of adjacent, supplementary angles.

Adjacent means next to each other.

Supplementary means that the measures of the two angles add up to equal 180 degrees.

Therefore, by definition, if x and y are linear pairs of angles, then x + y = 180.

Answer:

62.8

Step-by-step explanation:

Area of sector=(pi*r^2)*(theta/360)

Area of sector=(pi*100)*(72/360)=62.8

The area of the shaded sector AOB in terms of π is 20π units squared.

The area of a sector can be described as follows;

area of sector = ∅ / 360 × πr²

where

Therefore,

r = 10 units

∅ = 72°

Hence,

area of the sector = 72° / 360° × π10²

area of the sector = 7200 / 360 π

area of the sector = 20π units²

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Answer:

£0.50

Step-by-step explanation:

t = one cup of tea

c = one piece of cake

t + c = £1.10

2t + c = £1.70

the cost increases by £0.60 (£1.70 - £1.10) when you order one more cup of tea which means that one cup of tea costs £0.60

substitute £0.60 into t + c = £1.10

£0.60 + c = £1.10

rearrange to get c = £1.10 - £0.60 = £0.50

so one piece of cake costs £0.50

Answer:

x = 7

Explaination:

ABC = 40°

and BD bisects the angle so ABD = 20°

so 3x-1=20

solving for x gets us

x = 7

The length of the curve (and thus the total distance traveled by the particle along the curve) is

[tex]\displaystyle\int_0^{3\pi}\sqrt{x'(t)^2+y'(t)^2}\,\mathrm dt[/tex]

We have

x(t) = 3 sin²(t )   ==>   x'(t) = 6 sin(t ) cos(t ) = 3 sin(2t )

y(t) = 3 cos²(t )   ==>   y'(t) = -6 cos(t ) sin(t ) = -3 sin(2t )

Then

√(x'(t) ² + y'(t) ²) = √(18 sin²(2t )) = 18 |sin(2t )|

and the arc length is

[tex]\displaystyle 18 \int_0^{3\pi} |\sin(2t)| \,\mathrm dt[/tex]

Recall the definition of absolute value: |x| = x if x ≥ 0, and |x| = -x if x < 0.

Now,

• sin(2t ) ≥ 0 for t ∈ (0, π/2) U (π, 3π/2) U (2π, 5π/2)

• sin(2t ) < 0 for t ∈ (π/2, π) U (3π/2, 2π) U (5π/2, 3π)

so we split up the integral as

[tex]\displaystyle 18 \left(\int_0^{\pi/2} \sin(2t) \,\mathrm dt - \int_{\pi/2}^\pi \sin(2t) \,\mathrm dt + \cdots - \int_{5\pi/2}^{3\pi} \sin(2t) \,\mathrm dt\right)[/tex]

which evaluates to 18 × (1 - (-1) + 1 - (-1) + 1 - (-1)) = 18 × 6 = 108.

Answer:

Point-slope form: y-4=2(x+1)

Slope intercept form: y=2x+6

I hope this helps!

Answer:

[tex]y-4=2(x+1)[/tex]

Step-by-step explanation:

Point-slope form is equal to

[tex]y-y_1=m(x-x_1)[/tex]

where y and y1 are the known y coordinates of two points on the line, and x and x1 are the known x coordinates of two points on the line. All we need now is m, which is the slope:

[tex]4-2=m(-1-(-2))[/tex]

We can simplify negative one minus negative two as positive 1.

[tex]4-2=m(1)[/tex]

4 minus 2 is 2, so m times 1 is 2. That means m is 2.

Now, we have the slope, so we can convert to point-slope form using one of the two points. Let's use (-1, 4). We can plug those values in for x1 and y1:

[tex]y-4=2(x+1)[/tex]

Answer:

V = 2143.57 cm^3

Step-by-step explanation:

The volume of a sphere is

V = 4/3 pi r^3

The diameter is 16 so the radius is 1/2 of the diameter or 8

V = 4/3 ( 3.14) (8)^3

V =2143.57333

Rounding to the nearest hundredth

V = 2143.57 cm^3

Answer:

2143.57 cm^3

Step-by-step explanation:

V = 4/3 * 3.14 * r^3

r = 1/2 * 16 = 8

So V = 4/3 * 3.14 * 8^3

= 2143.57 cm^3.

Answer:

224π in^2

Step-by-step explanation:

Just plug in the values,

Surface area=2πr(h+r) [Factoring]

r=7in

h=9in

2πr(h+r)=2π*7(9+7)=14π(16)=224π in^2

Answer:

0.25

Step-by-step explanation:

16/4 = 4

4/4 = 1

1/4 = 0.25

0.25/4 = 0.0625

0.0625/4 = 0.015625

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Answer:

A) U is called an upper triangular matrix because all entries below the principal diagonal element are zeros ( 0 )   since Uij = 0 if i >j  also

L is a lower triangular matrix because all entries above the principal diagonal element are zero ( 0 )

B) sum of two upper triangular matrices = upper triangular matrix.

C) product of two upper triangular matrices = upper triangular matrix

Step-by-step explanation:

A) U is called an upper triangular matrix because all entries below the principal diagonal element are zeros ( 0 )   since Uij = 0 if i >j  also

L is a lower triangular matrix because all entries above the principal diagonal element are zero ( 0 ) since Lij = 0  if i < j

B) To prove that sum of two upper triangular matrices

attached below

C) Prove or disprove that product of two upper triangular matrices is an upper triangular matrix

attached below

Answer:

The answer is "720"

Step-by-step explanation:

The amount of different slates candidates:

[tex]n=\frac{N!}{(N-k)!}\\\\[/tex]

   [tex]=\frac{10!}{(10-3)!}\\\\=\frac{10!}{7!}\\\\=\frac{10\times 9 \times 8 \times 7! }{7!}\\\\=10\times 9 \times 8\\\\=90\times 8\\\\=720[/tex]

Answer:

Line of Symmetry i think

Line of symmetry best describes the line that divides a design so that every point on one side of the line coincides with a point on the other side of the line.

Coordinate Geometry (or the analytic geometry) describes the link between geometry and algebra through graphs involving curves and lines.

A line of symmetry is a line that divides a figure into two congruent parts such that if one part is folded over the line of symmetry, it will coincide with the other part.

In other words, each point on one side of the line of symmetry is equidistant from the line as the corresponding point on the other side of the line.

The line that divides a design so that every point on one side of the line coincides with a point on the other side of the line is called the Line of Symmetry.

Hence,  line of symmetry best describes the line that divides a design so that every point on one side of the line coincides with a point on the other side of the line.

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Answer:

Step-by-step explanation:

I am assuming i is the imaginary number:

Factor:

(3 + i)x - (4-2i) = 0.

In order for this to equal 0, x must be equal to 1-i.

I don't want to be reported to so take my word for it.

Also I plugged it into wolfram alpha so if it is wrong, blame the most powerful math equation solver available on the internet.

Using BTS he properties, find the unit's digit of the cube of each of the following numbers

Answer:

[tex]thank \: you[/tex]

Answer:

3003 ways

Step-by-step explanation:

(7+8)C5

= 15C5

= 15!/(5!10!)

= 3003