45 – [43 - {9 – 4 (3 – 8 ÷ 2 + 6)}]

First, recall that

cos(A - B) = cos(A) cos(B) + sin(A) sin(B)

so you just need to find cos(A) and sin(B).

Since both A and B end in the second quadrant, you know that

• cos(A) and cos(B) are both negative

• sin(A) and sin(B) are both positive

Then from the Pythagorean identity, you get

cos²(A) + sin²(A) = 1   ==>   cos(A) = -√(1 - sin²(A)) = -2√10/7

cos²(B) + sin²(B) = 1   ==>   sin(B) = +√(1 - cos²(B)) = √21/5

You'll end up with

cos(A - B) = (-2√10/7) (-2/5) + (3/7) (√21/5)

… = (4√10 + 3√21)/35

(which makes the last sentence in the question kind of confusing, because this expression doesn't get much simpler and it's certainly not a rational number)

The value of cos(A - B) is approximately 23/25

Given that A and B are in the second quadrant, we have

To find cos(A - B), we have to use trigonometric functions

cos(A - B) = cosAcosB + sinAsinB ...equation(i)

but

[tex]cos^2A + sin^2A =1 \\cos^2A = 1 - sin^2A\\cos^2A = 1 - (\frac{3}{7})^2 = 1 - \frac{9}{49}= cosA= -\frac{2\sqrt{5} }{7}[/tex]

Having the value of cos A, let's solve for cosB

cos B = -2/5

[tex]sin^2B = 1-cos^2B\\sin^2B = 1-(-\frac{2}{5})^2= 1-\frac{4}{25}\\sinB = \sqrt{\frac{21}{25} }=\frac{\sqrt{21} }{5}[/tex]

substituting the values if sinA, cosA, sinB, cosB into equation(i) above;

[tex]cos(A-B)=cosAcosB+sinAsinB\\cos(A-B)=(-\frac{2\sqrt{5} }{7})(-\frac{2}{5})+(\frac{3}{7})(\frac{\sqrt{21} }{5})\\cos(A-B)=\frac{3\sqrt{21}+4\sqrt{5} }{35} \\cos(A-B) = 23/35[/tex]

The value of cos(A-B) is given above

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Answer:

x=7/3

Step-by-step explanation:

8 ^ (x - 1 ) = 16

We need to rewrite 8 as 2^3  and 16 as 2^4

2^3 ^ (x - 1 ) = 2^4

We know that a^b^c = a^(b*c)

2^(3(x-1)) = 2^4

The bases are the same so the exponents are the same

3(x-1) = 4

Distribute

3x-3 = 4

Add 3 to each side

3x-3+3 = 4+3

3x = 7

Divide by 3

3x/3 = 7/3

x=7/3

Answer:

16

Step-by-step explanation:

First you calculate the value

(2)÷2^-2

Then you simplify

2^4

=16

Answer:

D should be the anwser if im not mistaken!

Step-by-step explanation:

rp= 6 cm and as u can tell the side where q,s lies is a little bit longer so itll be 1 cm longer the r,p!!

Answer:

7

Step-by-step explanation:

Triangle Proportionality Theorem : If a line parallel to one side of a triangle intersects the other two sides of the triangle, then the line divides these two sides proportionally.

[tex]\frac{RP}{PT}[/tex] = [tex]\frac{SQ}{QT}[/tex]     Set up proportions

[tex]\frac{6}{18}[/tex] = [tex]\frac{x}{21}[/tex]        Cross multiply

18x = 126   Divide to isolate x

x = 7

Answer:

Which subject is this . please tell

Answer:

see explanation

Step-by-step explanation:

1

(a)

Calculate slope m using the slope formula

m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]

with (x₁, y₁  = (8, 3) and (x₂, y₂ ) = (10, 7)

m = [tex]\frac{7-3}{10-8}[/tex] = [tex]\frac{4}{2}[/tex] = 2

(b)

Given a line with slope m then the slope of a line perpendicular to it is

[tex]m_{perpendicular}[/tex] = - [tex]\frac{1}{m}[/tex] = - [tex]\frac{1}{2}[/tex]

(c)

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

Here m = - [tex]\frac{1}{2}[/tex] , then

y = - [tex]\frac{1}{2}[/tex] x + c ← is the partial equation

To find c substitute (8, 3) into the partial equation

3 = - 4 + c ⇒ c = 3 + 4 = 7

y = - [tex]\frac{1}{2}[/tex] x + 7 ← equation of perpendicular line

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

2

(a)

with (x₁, y₁ ) = (3, 5) and (x₂, y₂ ) = (4, 4)

m = [tex]\frac{4-5}{4-3}[/tex] = [tex]\frac{-1}{1}[/tex] = - 1

(b)

[tex]m_{perpendicular}[/tex] = - [tex]\frac{1}{-1}[/tex] = 1

(c)

y = x + c ← is the partial equation

To find c substitute (3, 5) into the partial equation

5 = 3 + c ⇒ c = 5 - 3 = 2

y = x + 2 ← equation of perpendicular line

Answer:

The LCM of 100 and 120 is 600.

The LCM of 5 and 120 is 120.

LCM of 5 and 100 is 100.

Step-by-step explanation:

I think this is the answer . If it is not sorry .

Answer:

Blade A : H(θ) = 75 + 50 sin θ

Blade B : H(θ) = 75 + 50 sin(θ + 90° )

Blade C : H(θ) = 75 + 50 sin( θ + 180° )  

Blade D : H(θ) = 75 + 50 sin( θ + 270° )

Step-by-step explanation:

Given data :

Diameter of blade = 50 m

overall height = 125 m

The four blades : Blade A , Blade B, Blade C, Blade D  all moves in same direction hence they make 90° to each other.

Lets assume The blades are standing at  θ with the horizontal

The four equation  modelling the heights :

Blade A : H(θ) = 75 + 50 sin θ

Blade B : H(θ) = 75 + 50 sin(θ + 90° )

Blade C : H(θ) = 75 + 50 sin( θ + 180° )  

Blade D : H(θ) = 75 + 50 sin( θ + 270° )

Answer:

(x+2y)(x+2y)

x²+2xy+2xy+2y²

x²+4xy+2y²

(2x+3y)(2x+3y)

4x²+6xy+6xy+9y²

4x²+12xy+9y²

Sheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeesh

Answer:

Option (D)

Step-by-step explanation:

Length of the bar EG = 1.6x

If F is a point on the bar such that,

EF + FG = EG

Measure of segment EF = 6

Measure of FG = x

By substituting measures of each side,

6 + x = 1.6x

1.6x - x = 6

0.6x = 6

x = 10

Length of EG = x + 6

                      = 10 + 6

                      = 16 units

Option (D) will be the correct option.

From the given diagram , the length of EG is 16

Given :

From the diagram , we can see that

EF=6, FG=x and EG=1.6x

We know that , EG=EF+FG

[tex]EG=EF+FG\\1.6x=6+x\\Solve \; for \; x\\1.6x-x=6\\0.6x=6\\divide by \; 0.6\\x=10[/tex]

Now we find out EG

EG=1.6x

Substitute 10 for x

[tex]EG=1.6x=1.6(10)=16\\[/tex]

EG=16

The length of EG is 16

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Answer:

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Answer:

Plotting the points on graph and joining them gives a right angle triangle

Answer:

right angle triangle

Step-by-step explanation:

Slope = (Y1-Y2)/(X1-X2)

The slope of AC is 1/3. The slope of BC is -3. Therefore AC is perpendicular to BC (right angle).

[tex] \sf \: \frac{5}{21 } \: rounded \: to \: 3 \: decimal \: places \: is \: \boxed{ \underline{ \bf0.238}}. \\ \longrightarrow \sf \: Just \: divide \: 5 \: by \: 21 \: upto \: 3 \: decimal \: places \\ \sf \: to \: get \: the \: answer.[/tex]

Answer:

B

Step-by-step explanation:

For the lines to be parallel.

The 2 given angles are corresponding and congruent, that is

4x - 12 = 3x + 17 ( subtract 3x from both sides )

x - 12 = 17 ( add 12 to both sides )

x = 29 → B

The value of x will be 29°. Then the correct option is B.

If two lines are parallel, then the third line. The corresponding angles are equal angles.

We know that the angle (3x + 17) and (4x – 12) are corresponding angle.

(3x + 17) = (4x – 12)

4x – 3x = 17 + 12

          x = 29°

The value of x will be 29°.

Then the correct option is B.

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Answer:

Step-by-step explanation:

5.1, please this is just a guess from using my head to calculate

Answer:

18

Step-by-step explanation:

X^2 - 7 =

Since we need to evaluate the expression when X = 5, we replace X with 5.

= 5^2 - 7

Now, according to the correct order of operations, we need to do the exponent first. 5^2 = 5 * 5 = 25

= 25 - 7

Finally, we subtract.

= 18

Answer: 18

Answer:

10 ft, 20ft and 25 ft.

Step-by-step explanation:

10 ft, 20ft and 25 ft.

This will make a triangle as 25 < (10 + 20).

Answer:

Solution given:

one side of a triangle must be less than the sum of two other side .

by making these sense:

3<10+20

10<20+3

20<10+3not true

these three side are not possible.

again

10<20+25

20<25+10

25<20+10

these three side are true so

required side are:

Side 1:10

Side 2:25

Side 3:20

Answer:

please see the answer in the picture.

Answer:

14

Step-by-step explanation:

7*4*1/2=14

Answer:

10.75

11

Step-by-step explanation:

the mean is the average, so add up all of the values and divide by 8 because there are 8 values :

(11 + 17 + 14 + 11 + 4 + 7 + 11 + 11)/8 = 10.75

the median is the middle value when the numbers are written in ascending or descending order :

4, 7, 11, 11, 11, 11, 14, 17

we can cross out the values on the ends, to get to the middle. if we do this, we are left with 11, 11

find the average of these numbers :

which is 11.

Answer:

firstable give c+b a polynomial value like x

so its will be x^2+11x+30

after the we have to factor it

30=6×5

and 11=6+5

so its will become

(x+6)×(x+5)=x^2+11x+30

x=c+d

(c+d+6)×(c+d+5)=(c+d)^2+11(c+d)+30

have a great day

Answer:

The choose (D)

D. Translate y = |x| up 4 units and shade inside the V.

Answer:

leg = 18

hypotenuse = 18 sqrt(2)

Step-by-step explanation:

We know that sin theta = opp side / hypotenuse

sin 45 = 18 / hyp

hyp sin 45 = 18

hyp = 18 / sin 45

hyp = 18 sqrt(2)

Since this is an isosceles triangle ( the two angles are the same measure), the two legs have to be the same length

leg = 18

the lengths of the other leg and the hypotenuse

is 18 units and 18[tex]\sqrt{2}[/tex]units respectively.

Answer:

Solution given:

Let <C=<B=45°

AB=18 units

BC=?

AC=?

again

By using

By usingspecial right triangle ratios

sin C=opposite/hypotenuse=AB/AC=18/AC

Sin 45=18/AC

AC=18/sin45

AC=hypotenuse=18[tex]\sqrt{2}[/tex]units

again

Tan A=opposite/adjacent=BC/AB=BC/18

Tan45=BC/18

BC=Tan45*18

BC=length of another leg=18 units.

Answer:

263.25

Step-by-step explanation:

250 x .053 (5.3%) = 13.25 tax

250 + 13.25 = 263.25 price plus sales tax

Answer:

263.25

Step-by-step explanation:

Frequency is the number of incidences of an occasion or value. A frequency table that displays the number of incidences of the goods and the number of times, and the further discussion can be defined as follows:

Calculation:

[tex]lower\ \ \ \ \ \ \ \ \ upper \ \ \ \ \ \ \ \ \ frequency\\\\809\ \ \ \ \ \ \ \ \ 921 \ \ \ \ \ \ \ \ \ 3\\\\922 \ \ \ \ \ \ \ \ \ 1034 \ \ \ \ \ \ \ \ \ 3\\\\1035 \ \ \ \ \ \ \ \ \ 1147\ \ \ \ \ \ \ \ \ 2\\\\1148 \ \ \ \ \ \ \ \ \ 1260\ \ \ \ \ \ \ \ \ 4\\\\1261 \ \ \ \ \ \ \ \ \ 1373 \ \ \ \ \ \ \ \ \ 4\\\\1374 \ \ \ \ \ \ \ \ \ 1486\ \ \ \ \ \ \ \ \ 4[/tex]

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Answer:

8? not sure tho....

Step-by-step explanation:

Answer:

see below

Step-by-step explanation:

Part 1:

(512) ^ 1/3

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

(2197) ^ 1/3

8

-----

13

The scale factor is 8:13

Part 2

The ratios of the areas is related by scale factor squared

8^2

-----

13^2

64      

------  

169

Part 3

64       960

------  = ----------------

169     SA larger

Using cross products

64 * SA = 169 * 960

64 SA = 162240

Divide each side by 64

64 SA/ 64 = 162240 / 64

SA = 2535

2535 cm^2

Multiply each payout by the corresponding probability and take the total:

E[X] = 0×0.5 + 5×0.2 + 8×0.15 + 10×0.1 + 15×0.05 = 3.95

The expected value = 3.92

"It describes the average of a discrete set of variables based on their associated probabilities."

[tex]E(x)=\Sigma[ xP(x)][/tex]

Multiply each value of the random variable by its probability and add the products.

For given question,

We have been given a payout probability distribution.

We need to find the expected value of the winnings.

First we multiply each value of the random variable by its probability .

0 × 0.5 = 0

5 × 0.2 = 1

8 × 0.15 = 1.2

10 × 0.1 = 1

15 × 0.05 = 0.75

Now, we find the sum of above products.

0 + 1 + 1.2 + 1 + 0.75 = 3.95

By using the formula of expected value,

[tex]\Rightarrow E(x)=\Sigma[ xP(x)]\\\\\Rightarrow E(x)=3.92[/tex]

Therefore, the expected value = 3.92

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