Can anyone please help : show that cos^{2} (θ)= 1 + cos(2θ) / 2 , using the compound angle formula

Answer:

C, D, E and F

Step-by-step explanation:

Given

4x+5y=18

6x−5y=20

Required

Determine which procedure will result in a single equation in one variable

To do this; we'll test each of the options

A. Subtract the first equation from the second equation.

[tex](6x - 5y=20) - (4x+5y=18)[/tex]

[tex]6x - 4x - 5y - 5y = 20 - 18[/tex]

[tex]2x - 10y = 2[/tex] --- This didn't produce the desired result

B.  Subtract the second equation from the first equation.

[tex](4x+5y=18) - (6x - 5y=20)[/tex]

[tex]4x - 6x + 5y + 5y =18 - 20[/tex]

[tex]-2x + 10y = -2[/tex] --- This didn't produce the desired result

C. Multiply the first equation by 18; multiply the second equation by 18; add the equations.

First Equation

[tex]18 * (4x+5y=18)[/tex]

[tex]72x + 90y = 324[/tex]

Second Equation

[tex]18 * (6x - 5y=20)[/tex]

[tex]108x - 90y = 360[/tex]

Add Resulting Equations

[tex](72x + 90y = 324) + (108x - 90y = 360)[/tex]

[tex]72x + 108x + 90y - 90y = 324 + 360[/tex]

[tex]72x + 108x = 324 + 360[/tex]

[tex]180x = 684[/tex] --- This procedure is valid

D. Multiply the first equation by − 6; multiply the second equation by 4; add the two equations.

First Equation

[tex]-6 * (4x+5y=18)[/tex]

[tex]-24x - 30y = -108[/tex]

Second Equation

[tex]4 * (6x - 5y=20)[/tex]

[tex]24x - 20y = 80[/tex]

Add Resulting Equations

[tex](-24x - 30y = -108) + (24x - 20y = 80)[/tex]

[tex]-24x + 24x - 30y -20y = -108+ 80[/tex]

[tex]-50y = -28[/tex]

[tex]50y = 28[/tex]  --- This procedure is valid

E. Multiply the first equation by 3; multiply the second equation by − 2; add the two equations.

First Equation

[tex]3 * (4x+5y=18)[/tex]

[tex]12x + 15y = 54[/tex]

Second Equation

[tex]-2 * (6x - 5y=20)[/tex]

[tex]-12x + 10y = -40[/tex]

Add Resulting Equations

[tex](12x + 15y = 54) + (-12x + 10y = -40)[/tex]

[tex]12x - 12x + 15y - 10y =54 - 40[/tex]

[tex]5y = 14[/tex]  --- This procedure is valid

F. Multiply the first equation by 3; multiply the second equation by 2; subtract the equations in any order

First Equation

[tex]3 * (4x+5y=18)[/tex]

[tex]12x + 15y = 54[/tex]

Second Equation

[tex]2 * (6x - 5y=20)[/tex]

[tex]12x - 10y = 40[/tex]

Subtract equation 1 from 2 or 2 from 1 will eliminate x;

Hence, the procedure is also valid;

Answer:

The unknown integer that solves the equation is 6.

Step-by-step explanation:

In order to find the missing number, we can set up an equation as if we are solving for x.

x + (-8) = -2

Add 8 on both sides of the equation.

x = 6

So, the unknown integer is 6.

Answer:

6

Step-by-step explanation:

6 plus -8 is -2

Work Shown:

(9^x)/(3^y)

( (3^2)^x )/(3^y)

( 3^(2x) )/( 3^y )

3^(2x-y)

3^2 .... use the equation 2x-y = 2

9

Complete Question

It has been found that 26% of men 20 years and older suffer from hypertension (high blood pressure) and 31.5% of women are hypertensive. A random sample 150 of each gender was selected from recent hospital records, and the following results were obtained.

Men. 43 patients had high blood pressure

Woman. 52 patients had high blood pressure.

Answer:

The  95% confidence interval is  

      [tex]- 0.1651 < p_m - p_f <0.0451[/tex]

This mean that there is a 95 % confidence that the difference between the true proportions of male and  female that are hypertensive  is within this interval and given that the interval contains zero then there is no statistically significant difference between the genders that are hypertensive        

Step-by-step explanation:

From the question we are told that

    The  sample size for male is  [tex]n_1 = 150[/tex]

    The  number of male that are hypertensive is  [tex]m = 42[/tex]

    The  sample size of female is  [tex]n_2 = 150[/tex]

     The  number of female that are hypertensive is [tex]q = 52[/tex]

The proportion of male that are hypertensive is mathematically represented as

         [tex]\r p_m = \frac{43}{150}[/tex]

         [tex]\r p_m = 0.287[/tex]          

The proportion of female that are hypertensive is mathematically represented as

       [tex]p_f = \frac{52}{150}[/tex]

      [tex]p_f = 0.347[/tex]

From the question we are told that confidence level is 95%, hence the level of significance is mathematically represented as

       [tex]\alpha = 100 -95[/tex]

      [tex]\alpha =5\%[/tex]

     [tex]\alpha =0.05[/tex]

Next we obtain the critical value of  [tex]\frac{ \alpha }{2}[/tex] from  the normal distribution table, the value is  

           [tex]Z_{\frac{ \alpha }{2} } = 1.96[/tex]

Generally the margin of error is mathematically represented as

          [tex]E = Z_{\frac{\alpha }{2} } * \sqrt{\frac{ \r p_m (1- \r p_m )}{n_1} + \frac{ \r p_f (1- \r p_f )}{n_2} }[/tex]

substituting value

         [tex]E = 1.96 * \sqrt{\frac{ 0.287 (1- 0.287 )}{150} + \frac{ 0.347 (1- 0.347 )}{150} }[/tex]

         [tex]E = 0.1051[/tex]

The  95% confidence interval is mathematically represented as  

           [tex](\r p_m - \r p_f ) - E < p_m - p_f < (\r p_m - \r p_f ) + E[/tex]

substituting values

          [tex]( 0.287 - 0.347 ) - 0.1051 < p_m - p_f <( 0.287 - 0.347 ) + 0.1051[/tex]    

           [tex]- 0.1651 < p_m - p_f <0.0451[/tex]

This mean that there is a 95 % confidence that the difference between the true proportion is within this interval and given that the interval contains zero then there is no statistically significant difference between the genders that are hypertensive.

Answer:

a

Step-by-step explanation:

its a

The answer is m = 3000 - 40h

m = 1200 + 50h.

The answer is option A.

Problem-solving is the act of defining a problem; figuring out the reason for the hassle; identifying, prioritizing, and selecting options for an answer; and enforcing an answer.

Problem-solving begins with identifying the issue. For example, a teacher would possibly need to parent out a way to enhance scholar performance on writing scalability take a look at it. To do this, the trainer will assess the writing tests seeking out regions for improvement.

Learn more about Problem-solving here: https://brainly.com/question/13818690

#SPJ2

Answer:

10,9.75,9.5,9.25,9, 8.75 , 8.5, 8.25, 8...

Step-by-step explanation:

Subtract 0.25 from each to find the next number

Answer:

8.25

Step-by-step explanation:

If you substract .25 from each number until you get to a8 you will get 8.25

Answer:

[tex]m = 10[/tex]

Step-by-step explanation:

Looking at the angles, we can see that this is a 30-60-90 triangle.

The side that is with the 30° angle and the 90° angle is represented by [tex]x\sqrt{3}[/tex].

So let's find x.

[tex]x\sqrt{3} = 5\sqrt{3}[/tex]

Divide both sides by [tex]\sqrt{3}[/tex]:

[tex]x = 5[/tex].

Now the hypotenuse is always [tex]2x[/tex] (the leg with the 90° and 60° is just x.) So,

[tex]2x = 2\cdot5 = 10[/tex].

Hope this helped!

Answer: x=29

Step-by-step explanation:

[tex]x-21=8[/tex]

add 21 to both sides

[tex]x-21+21=8+21[/tex]

[tex]21+8=29\\[/tex]

[tex]x=29[/tex]

Answer:

(a) The probability that a study participant has a height that is less than 67 inches is 0.4013.

(b) The probability that a study participant has a height that is between 67 and 71 inches is 0.5586.

(c) The probability that a study participant has a height that is more than 71 inches is 0.0401.

(d) The event in part (c) is an unusual event.

Step-by-step explanation:

The complete question is: In a survey of a group of​ men, the heights in the​ 20-29 age group were normally​ distributed, with a mean of 67.5 inches and a standard deviation of 2.0 inches. A study participant is randomly selected. Complete parts​ (a) through​ (d) below. ​(a) Find the probability that a study participant has a height that is less than 67 inches. The probability that the study participant selected at random is less than inches tall is nothing. ​(Round to four decimal places as​ needed.) ​(b) Find the probability that a study participant has a height that is between 67 and 71 inches. The probability that the study participant selected at random is between and inches tall is nothing. ​(Round to four decimal places as​ needed.) ​(c) Find the probability that a study participant has a height that is more than 71 inches. The probability that the study participant selected at random is more than inches tall is nothing. ​(Round to four decimal places as​ needed.) ​(d) Identify any unusual events. Explain your reasoning. Choose the correct answer below.

We are given that the heights in the​ 20-29 age group were normally​ distributed, with a mean of 67.5 inches and a standard deviation of 2.0 inches.

Let X = the heights of men in the​ 20-29 age group

The z-score probability distribution for the normal distribution is given by;

                          Z  =  [tex]\frac{X-\mu}{\sigma}[/tex]  ~ N(0,1)

where, [tex]\mu[/tex] = population mean height = 67.5 inches

            [tex]\sigma[/tex] = standard deviation = 2 inches

So, X ~ Normal([tex]\mu=67.5, \sigma^{2}=2^{2}[/tex])

(a) The probability that a study participant has a height that is less than 67 inches is given by = P(X < 67 inches)

      P(X < 67 inches) = P( [tex]\frac{X-\mu}{\sigma}[/tex] < [tex]\frac{67-67.5}{2}[/tex] ) = P(Z < -0.25) = 1 - P(Z [tex]\leq[/tex] 0.25)

                                                                 = 1 - 0.5987 = 0.4013

The above probability is calculated by looking at the value of x = 0.25 in the z table which has an area of 0.5987.

(b) The probability that a study participant has a height that is between 67 and 71 inches is given by = P(67 inches < X < 71 inches)

    P(67 inches < X < 71 inches) = P(X < 71 inches) - P(X [tex]\leq[/tex] 67 inches)

    P(X < 71 inches) = P( [tex]\frac{X-\mu}{\sigma}[/tex] < [tex]\frac{71-67.5}{2}[/tex] ) = P(Z < 1.75) = 0.9599

    P(X [tex]\leq[/tex] 67 inches) = P( [tex]\frac{X-\mu}{\sigma}[/tex] [tex]\leq[/tex] [tex]\frac{67-67.5}{2}[/tex] ) = P(Z [tex]\leq[/tex] -0.25) = 1 - P(Z < 0.25)

                                                                = 1 - 0.5987 = 0.4013

The above probability is calculated by looking at the value of x = 1.75 and x = 0.25 in the z table which has an area of 0.9599 and 0.5987 respectively.

Therefore, P(67 inches < X < 71 inches) = 0.9599 - 0.4013 = 0.5586.

(c) The probability that a study participant has a height that is more than 71 inches is given by = P(X > 71 inches)

      P(X > 71 inches) = P( [tex]\frac{X-\mu}{\sigma}[/tex] > [tex]\frac{71-67.5}{2}[/tex] ) = P(Z > 1.75) = 1 - P(Z [tex]\leq[/tex] 1.75)

                                                                 = 1 - 0.9599 = 0.0401

The above probability is calculated by looking at the value of x = 1.75 in the z table which has an area of 0.9599.

(d) The event in part (c) is an unusual event because the probability that a study participant has a height that is more than 71 inches is less than 0.05.

Answer:

Translated according to the rule (x, y)⇒ (x+7, y+1)  , reflected across the  x-axis

Step-by-step explanation:

Transformation involves changing the orientation, or even size of a given figure or object to produce its image. The methods of transformation include; translation, rotation, reflection, and dilation.

Comparing the pentagon ABCDE and A”B”C”D”E”, the two transformations applied are reflection across the x-axis first, then translation.

Answer:

The answer is "Choice B, C, and F is correct".

Step-by-step explanation:

The following are choices, which is missing in the question, that can be defined as follows:

A) {x| x ≥ 3} is the domain.  

B) The set shall be {y| y ≥ –1}.  

C) over the interval  (–∞, 3), is the function, that decreases.  

D) it's over the duration the function increases its value, that is (–1, ∞).  

E) The symmetry axis will be x = – 1.  

F) vertex is (3, – 1).

Answer:

the answers are b, c, e

Step-by-step explanation:

i just took the test

Answer:

216

Step-by-step explanation:

If you just paint the surface of the cube, then the inside of the cube would not have any of their faces painted red.

Just looking at the cube from a side view, you would realize that there would be a smaller cube, 6 x 6 x 6 (not 7 since you have to account for both the top side and the bottom side), and so that is the answer, 6 ^ 3, which is 216.

Answer:

216

Step-by-step explanation:

8 * 8 * 8 = 512

8 * 8 = 64

Each face is 64 cubes, overlapping at the edges, with 6 faces total.

16 + 12 = 28 for each overlapping cube on each side

64 * 6 = 384

384 - 2(28) = 328

Top & Bottom dealt with, overlap from them is 56 units total, 14 units on top and bottom of each face..

64 - 14 = 50

50 * 2 = 100

Front & Back dealt with.

328 - 100 = 228

64 - 28 = 36

36 * 2 = 72

228 - 72 = 156

...

OR

6^3 = 216

Answer:

x=(n+12)π, y=mπ∴x=n+12π, y=mπ and z = rπ where n∈I, m∈I, r∈I

Step-by-step explanation:

∴ LHS ≤ 2 and RHS ≥ 2

So, sin2 x = 1, cos2 y = 1 and sec2 z = 1

∴x=(n+12)π, y=mπ∴x=n+12π, y=mπ and z = rπ where n∈I, m∈I, r∈I

Answer:

300%

Step-by-step explanation:

1 year = 12 months

percent = part/whole * 100%

percent = 12/4 * 100% = 300%

Answer:

please can u follow me I've started following you

Answer:

The correct option is D

P(A or B) = 1.30

Step-by-step explanation:

Given two independent (or mutually exclusive) events with P(A) = 0.60, and P(B) = 0.70

P(A or B) = P(A) + P(B)

= 0.60 + 0.70

= 1.30

This is however absurd, as the probability of an event can only be less than or equal to 1, and not less than 0.

Based on the information given, the value of then P(A or B) will be D. 1.30.

From the information given, A and B are independent events with P( A) = 0.60 and P( B) = 0.70.

Then, the value of P(A or B) will be calculated thus:

= 0.60 + 0.70

= 1.30

In conclusion, the correct option is D.

Learn more about probability on:

https://brainly.com/question/24756209

Answer:

wrong position of tan 64

Answer:

The diameter that will reward with the largest pizza is 14 in

Step-by-step explanation:

The perimeter of a sector of a circle is:

P = 2r + l

l = rθ

P = 2r + rθ

P=28 inches

28=2r + rθ

28-2r=rθ

θ=(28-2r/r)

=(2*14 - 2*r)/r

=2(14-r)/r

Area of the sector of the circle is:

A = r²/2 * θ

A = r²/2 * 2(14 - r)/r

A = r² * (14 - r)/r

A = r(14 - r)

A = 14r - r²

For the maximum area:

A = 14r - r²

A' = 14 - 2r

Set A' = 0

14 - 2r = 0

14= 2r

r = 7 in

The diameter (D) of the circle is twice of the radius:

D = 2r = 2 * 7= 14 in

The maximum area is:

A = 14r - r²

r = 7 in

A = 14 * 7 - 7²

A = 98 - 49

A = 49 in²

Answer:

The z-score is [tex]z = 0.6[/tex]

The percentile is  [tex]p(Z < 0.6) = 72.57\%[/tex]

Step-by-step explanation:

From the question we are told that

   The  data value is  0.6 standard deviations above the mean i.e  [tex]x = \mu + 0.6 \sigma[/tex]

Where  [tex]\mu[/tex] is the population mean and [tex]\sigma[/tex] is the standard deviation

Generally the z-score is mathematically represented as

        [tex]z = \frac{x - \mu }{\sigma }[/tex]

=>     [tex]z = \frac{(\mu + 0.6\sigma ) - \mu }{\sigma }[/tex]

=>    [tex]z = 0.6[/tex]

The percentile is obtained from the z-table and the value is

     [tex]p(Z < 0.6) = 0.7257[/tex]

=>   [tex]p(Z < 0.6) = 72.57\%[/tex]

Answer:

Problem 1)       [tex] m = \dfrac{1}{4} [/tex]     [tex] slope_{perpendicular} = -4 [/tex]

Problem 2)      [tex] m = \dfrac{1}{3} [/tex]     [tex] slope_{perpendicular} = -3 [/tex]

Step-by-step explanation:

[tex] slope = m = \dfrac{y_2 - y_1}{x_2 - x_1} [/tex]

[tex] slope_{perpendicular} = \dfrac{-1}{m} [/tex]

Problem 1) M(9,6), N(1,4)

[tex] slope = m = \dfrac{6 - 4}{9 - 1} = \dfrac{2}{8} = \dfrac{1}{4} [/tex]

[tex] slope_{perpendicular} = \dfrac{-1}{\frac{1}{4}} = -4 [/tex]

Problem 2) M(-2,2), N(4,-4)

[tex] slope = m = \dfrac{4 - 2}{4 - (-2)} = \dfrac{2}{6} = \dfrac{1}{3} [/tex]

[tex] slope_{perpendicular} = \dfrac{-1}{\frac{1}{3}} = -3 [/tex]

Answer:

Solution : y = 4x - 8

Step-by-step explanation:

The first thing we want to do is isolate t², rather than t. Why? As you can see when we substitute t² into the second equation, it will be easier than substituting t, as t is present in the form t². So, let's isolate t² in the first equation --- ( 1 )

x = t² + 2,

t² = x - 2

Now let's substitute this value of t² in the second equation --- ( 2 )

y = 4t²,

y = 4(x - 2),

y = 4x - 8 ~ And hence our solution is option c.

Answer:

False

Step-by-step explanation:

Regression model is a set of statistical process which estimates the relationship between two variables. The one variable is dependent variable and the other is independent variable. The statistician should not use printout C to perform a t-test in regression model.

Answer:

1. Make a list of activities and the number of students:

Watching TV: 32

Talking on the phone: 41

Video games: 24

Reading: 15

2. Then combine the data in a bar graph as shown in the picture

Answer:

[tex]\frac{1}{2}[/tex]

Step-by-step explanation:

In a 6 sided die, the numbers that are possible to be rolled are

1, 2, 3, 4, 5, and 6.

We know that the numbers 2, 3, and 5 are prime, while 1, 4, and 6 are not.

3 out of the 6 numbers are prime, therefore 3 out of the 6 numbers are not prime.

So the fraction is [tex]\frac{3}{6}[/tex]

This simplifies to [tex]\frac{1}{2}[/tex].

Hope this helped!

Answer:

1/2

Step-by-step explanation:

the prime numbers between 1 and 6 inclusive are:  2, 3, 5  (i.e 3 possible outcomes)

the non prime numbers are : 1, 4 and 6 (i.e 3 possible outcomes)

for each roll, the total number of possible outcomes is 6 (because its a 6-sided die)

P(does not roll a prime number) = P (rolls 1, 4 or 6)

= number of possible non-prime outcomes / total number of outcomes

= 3/6

= 1/2

Answer:

This is true

Step-by-step explanation:

Because a rational number can be expressed as going on forever.

Answer:

a) y = 4

b) RS = 26, ST = 19, RT = 45

Step-by-step explanation:

From the line given, the following vector equation is true, RS + ST = RT since R, S and T lies in the same straight line.

Given RS = 6y + 2, ST = 3y + 7, and RT = 14y - 11

On substituting this values into the equation above we will have;

6y+2+(3y+7) = 14y-11

6y+2+3y+7 = 14y-11

Collect the like terms

6y+3y-14y = -11-7-2

9y-14y = -20

-5y = -20

y = 20/5

y = 4

Since RS = 6y + 2

RS = 6(4)+2

RS = 24+2

RS = 26

ST = 3y + 7

ST = 3(4)+7

ST = 12+7

ST = 19

Also, RT = 14y - 11

RT = 14(4)-11

RT = 56-11

RT = 45

Answer:  [tex]\dfrac{(x+9)^2}{225}-\dfrac{(y+7)^2}{49}=1[/tex]

Step-by-step explanation:

The equation for a horizontal ellipse is: [tex]\dfrac{(x-h)^2}{a^2}-\dfrac{(y-k)^2}{b^2}=1[/tex]  where

Given: major axis (diameter on x) is 30 --> x-radius (a) = 15  -->  a² = 225

           minor axis (diameter on y) is 14 --> y-radius (b) = 7   --> b² = 49

           center (h, k) is (-9, -7)

Input those values into the equation for a horizontal ellipse and simplify:

  [tex]\dfrac{(x-(-9))^2}{15^2}-\dfrac{(y-(-7))^2}{7^2}=1\\\\\\\large\boxed{\dfrac{(x+9)^2}{225}-\dfrac{(y+7)^2}{49}=1}[/tex]  

Answer:

X+9=24

Or,x=24-9

:.x=15

Step-by-step explanation:

Answer:

B. x=15

Step-by-step explanation:

To find the solution to the equation, we must get x by itself on one side of the equation.

[tex]x+9=24[/tex]

9 is being added to x. The inverse of addition is subtraction. Subtract 9 from both sides of the equation.

[tex]x+9-9=24-9[/tex]

[tex]x=24-9[/tex]

[tex]x=15[/tex]

Let's check our solution. Plug 15 in for x.

[tex]x+9=24 (x=15)[/tex]

[tex]15+9=24[/tex]

[tex]24=24[/tex]

This checks out, so we know our solution is correct. The answer is B. x=15

Answer: 1860480

Step-by-step explanation:

Initially, there are 20 balls where 5 must be chosen in order.

The number of possible outcomes may be calculated using the concept of permutations.

The formula for permutations is:

nPr =n!/(n−r)!

where n represents the number of items and r represents the number of items to be selected.

The number of ways of selecting 5 balls in order out of 20 is:

20P5 = 20!/15!

= 1860480

To conclude, there are 1860480 possible outcomes.

Answer:

(a)

dependent

(b)

x = -3t - 12

y = -5t - 16

z = t

Step-by-step explanation:

2x - 3y - 9z = 24       Eq. 1

x + 3z = -12                Eq. 2

-3x + y - 4z = 20        Eq. 3

      2x - 3y - 9z = 24

(+)  -9x + 3y - 12x = 60     3 * Eq. 3

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

     -7x           -21z = 84     Eq. 4

       7x + 21z = -84          7 * Eq. 2

(+)    -7x - 21z = 84            Eq. 4

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

                  0  = 0

(a) The system is dependent.

(b)

z = t

x + 3z = -12                Eq. 2

x + 3t = -12

x = -3t - 12

2x - 3y - 9z = 24       Eq. 1

2(-3t - 12) - 3y - 9t = 24

-6t - 24 - 3y - 9t = 24

-3y - 15t = 48

-y - 5t = 16

-y = 5t + 16

y = -5t - 16

x = -3t - 12

y = -5t - 16

z = t

Answer: y=-2/3x-2/3

Step-by-step explanation:

concept to know: two lines that are perpendicular has opposite reciprocal slopes.

y=-2/3x+b

in order to find b or the y-intercept, we need to plug in a point

3=-2/3(-4)+b

3=8/3+b

b=-2/3

y=-2/3x-2/3

Hope this helps!! :)