Step-by-step explanation:
[tex] \boxed{cos^2x=\frac{1-cos2x}{2}}\\cos^2(45+A)+cos^2(45-A)=\frac{1-cos2(45+A)}{2}+\frac{1-cos2(45-A}{2}\\=\frac{1 - cos(90 +2A) }{2} + \frac{1 - cos(90 - 2A) }{2} \\ = \frac{2- ( - sin 2A) - sin2A}{2} \\ = \frac{2 + sin2A -sin2A }{2} \\ = \frac{2}{2} \\ = 1[/tex]
Step-by-step explanation:
Prove that
[tex]\cos^2(45+A)+\cos^2(45-A) =1[/tex]
We know that
[tex]\cos (\alpha \pm \beta) = \cos \alpha\cos \beta \mp \sin \alpha \sin\ beta)[/tex]
We can then write
[tex]\cos (45+A)=\cos 45\cos A - \sin 45\sin A[/tex]
[tex]\:\:\:\:\:\:\:\:= \frac{\sqrt{2}}{2}(\cos A - \sin A)[/tex]
Taking the square of the above expression, we get
[tex]\cos^2(45+A) = \frac{1}{2}(\cos^2A - 2\sin A \cos A + \sin^2A)[/tex]
[tex]= \frac{1}{2}(1 - 2\sin A\cos A)\:\:\;\:\:\:\:(1)[/tex]
Similarly, we can write
[tex]\cos^2(45-A) =\frac{1}{2}(1 + 2\sin A\cos A)\:\:\;\:\:\:\:(2)[/tex]
Combining (1) and (2), we get
[tex]\cos^2(45+A)+\cos^2(45-A)[/tex]
[tex]= \frac{1}{2}(1 - 2\sin A\cos A) + \frac{1}{2}(1 + 2\sin A\cos A)[/tex]
[tex]= 1[/tex]
The HCF of two numbers is 175. The LCM of these two numbers is 12600. Both numbers are greater than their HCF. Find the two numbers
Answer:
Hello,
Answer : 1400 and 1575
Step-by-step explanation:
Let's say a and b the ywo numbers
[tex]HCF(a,b)=a\vee b=175=5^2*7\\LCM(a,b)=a\wedge b=12600\\\\a*b=(a\vee b)*(a\wedge b)=(2^3*3^2*5^2*7)*(5^2*7)=2^3*3^2*(5^2*7^2)^2\\\\Both\ numbers\ are\ greater\ than\ their HCF\\a=175*k_1\\b=175*k_2\\\\k_1=2^3\ and\ k_2=3^2\\\\a=175*2^3=1400\\b=175*3^2=1575\\\\[/tex]
What integer is equal to 5!×2!?
Answer:
240
Step-by-step explanation:
! means factorial or to multiply by the previous number down to one so 5!=5*4*3*2*1=120 120*2=240.
In a study on the time that
a student required to obtain a college degree is randomly selected to 80
students and it is discovered that they have an average of 4.8 years (according to data from the National
Center for Education Statistics). Assuming s 2.2 years, construct an estimate of a confidence interval of the population mean. The confidence interval
the result contradicts the fact that 39% of students get their college degree in four years?
The 95% confidence interval of the population mean, in years, is (4.3, 5.3). 4 years is not part of the confidence interval, which means that it contradicts the fact that 39% of students get their college degree in four years.
-----------------------------
To solve this question, we need to find the confidence interval for the amount of time it takes the students to get the degree.
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
-----------------------------
The first step to solve this problem is finding how many degrees of freedom,which is the sample size subtracted by 1. So
df = 80 - 1 = 79
-----------------------------
95% confidence interval
Standard level of confidence, we have to find a value of T, which is found looking at the t table, with 79 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.95}{2} = 0.975[/tex]. So we have T = 1.9905.
-----------------------------
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 1.9905\frac{2.2}{\sqrt{80}} = 0.5[/tex]
In which s is the standard deviation of the sample and n is the size of the sample.
-----------------------------
The lower end of the interval is the sample mean subtracted by M. So it is 4.8 - 0.3 = 4.3 years.
The upper end of the interval is the sample mean added to M. So it is 4.8 + 0.3 = 5.3 years.
-----------------------------
The 95% confidence interval of the population mean, in years, is (4.3, 5.3). 4 years is not part of the confidence interval, which means that it contradicts the fact that 39% of students get their college degree in four years.
A similar question is given at https://brainly.com/question/24278748
You have $2,000 on a credit card that charges a 16% interest rate. If you want to pay off the credit card in 5 years, how much will you need to pay each month (assuming you don't charge anything new to the card)?
9514 1404 393
Answer:
$48.64
Step-by-step explanation:
The monthly payment amount is given by the amortization formula ...
A = P(r/n)/(1 -(1 +r/n)^(-nt))
where P is the loan amount, r is the annual interest rate compounded n times per year for t years.
Here, you have P=2000, r=0.16, n=12 (months per year), t=5 (years), so the payment is ...
A = $2000(0.16/12)/(1 -(1 +0.16/12)^(-12·5)) = $320/(12(0.54828942))
A ≈ $48.636 ≈ $48.64
You will need to pay $48.64 each month to pay off the charge in 5 years.
Find theta to the nearest tenth of a degree, if theta is between 0 degrees and 360 degrees for sin theta = 0.4649 with theta in quadrant 2
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Answer:
152.3°
Step-by-step explanation:
The arcsine function only gives angles in quadrants I and IV. Since this is a quadrant II angle, its value will be ...
θ = 180° -arcsin(0.4649) = 180° -27.7°
θ = 152.3°
A research center poll showed that 76% of people believe that it is morally wrong to not report all income on tax returns. What is the probability that someone does not have this belief?
Answer:
6/25
Step-by-step explanation:
P(have belief) =76/100 = 19/25
P (does not have belief) = 1-19/25 = 6/25
3. In A PQR, MZP=(4x-5),
m2Q=(8x-50), and MZR=(3x+10).
Which of the following best describes
APQR?
® Right triangle
® Isosceles triangle
© Equlateral triangle
Scalene triangle
Answer:
B
Step-by-step explanation:
The sum of all of them will result in 180. 15x-45=180. x=15. P=55, Q=70 and R=55. It's an isosceles triangle
Answer:
b
Step-by-step explanation:
its b
Calculate the Standard Deviation of the following set of data. 14, 15, 16, 16, 9, 3, 16, 20, 29, 12
Answer:
6,78
Step-by-step explanat
ion:data size :10
Sample mean:15
Standard sample deviation :6,782
Answer:
6,78
Step-by-step explanation:
You need a 75% alcohol solution. On hand, you have a 60 mL of a 55% alcohol mixture. You also have 85% alcohol mixture. How much of the 85% mixture will you need to add to obtain the desired solution?
You will need_____ mL of the 85% solution
60 mL=55% alcohol
?mL=85% alcohol
85×60÷55
=92.727 mL
I think do like this....I'm not sure
Hope this help you
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Answer:
120 mL
Step-by-step explanation:
Let x represent the amount of 85% solution needed. Then the total amount of alcohol in the mix is ...
0.55(60) +0.85(x) = 0.75(60 +x)
33 + 0.85x = 45 +0.75x . . . . . . . eliminate parentheses
0.85x = 12 +0.75x . . . . . . . . . .subtract 33
0.10x = 12 . . . . . . . . . . . . . . subtract 0.75x
x = 120 . . . . . . . . . . . . . . multiply by 10
You will need 120 mL of the 85% solution.
what is the perfect square of 96
Step-by-step explanation:
We determined above that the greatest perfect square from the list of all factors of 96 is 16.
Evaluate the expression for n = –8.
–2n − 6 =
Answer:
10Step-by-step explanation:
-2n - 6 = ?let n be -8-2 (-8) - 6 = ?= 10[tex]\tt{ \green{P} \orange{s} \red{y} \blue{x} \pink{c} \purple{h} \green{i} e}[/tex]
A lawyer commutes daily from his suburban home to his midtown office. The average time for a one-way trip is 24 minutes, with a standard deviation of 3.8 minutes. Assume the distribution of trip times to be normally distributed.
(a) What is the probability that a trip will take at least ½ hour?
(b) If the office opens at 9:00 A.M. and he leaves his house at 8:45 A.M. daily, what percentage of the time is he late for work?
(c) If he leaves the house at 8:35 A.M. and coffee is served at the office from 8:50 A.M. until 9:00 A.M., what is the probability that he misses coffee?
(d) Find the length of time above which we find the slowest 10% of trips.
(e) Find the probability that 2 of the next 3 trips will take at least one half
1/2 hour.
Answer:
Step-by-step explanation:
a) Probability-Above 30 min = 5.72% = .0572
b) Probability-Above 15 min = 99.11% = .9911
c) *Probability-Between 1 - 59.49% = .4051
d) 19.136 minutes z = -1.28
a) The probability that trip will take at least 1/2 hour will be 0.0606.
b) The percentage of time the lawyer is late for work will be 99.18%.
c) The probability that lawyer misses coffee will be 0.3659.
d) The length of time above which we find the slowest 10% of trips will be 0.5438.
e) The probability that exactly 2 out of 3 trips will take at least one half
1/2 hour is 0.0103.
What do you mean by normal distribution ?
A probability distribution known as a "normal distribution" shows that data are more likely to occur when they are close to the mean than when they are far from the mean.
Let assume the time taken for a one way trip be x .
x ⇒ N( μ , σ ²)
x ⇒ N( 24 , 3.8 ²)
a)
The probability that trip will take at least 1/2 hour or 30 minutes will be :
P ( x ≥ 30)
= P [ (x - μ) / σ ≥ (30 - μ) / σ ]
We know that , (x - μ) / σ = z.
= P [ z ≥ (30 - 24) / 3.8)]
= P [ z ≥ 1.578 ]
= 1 - P [ z ≤ 1.578 ]
Now , using the standard normal table :
P ( x ≥ 30)
= 1 - 0.9394
= 0.0606
b)
The percentage of the time the lawyer is late for work will be :
P ( x ≥ 15)
= P [ z ≥ -2.368 ]
= P [ z ≤ 2.368]
= 0.9918
or
99.18%
c)
The probability that lawyer misses coffee :
P ( 15 < x < 25 ) = P ( x < 25 ) - P ( x < 15)
= P [ z < 0.263] - P ( z < -2.368)
or
= 0.3659
d)
The length of time above which we find the slowest 10% of trips :
P( x ≥ X ) ≤ 0.10
= 0.5438
e)
Let's assume that y represents the number of trips that takes at least half hour.
y ⇒ B ( n , p)
y ⇒ B ( 3 , 0.0606)
So , the probability that exactly 2 out of 3 trips will take at least one half
1/2 hour is :
P ( Y = 2 )
= 3C2 × (0.0606)² × ( 1 - 0.0606)
= 0.0103
Therefore , the answers are :
a) The probability that trip will take at least 1/2 hour will be 0.0606.
b) The percentage of time the lawyer is late for work will be 99.18%.
c) The probability that lawyer misses coffee will be 0.3659.
d) The length of time above which we find the slowest 10% of trips will be 0.5438.
e) The probability that exactly 2 out of 3 trips will take at least one half
1/2 hour is 0.0103.
Learn more about normal distribution here :
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4)
Write an inequality for the graph below. If necessary, use
<= for < or >= for .
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Answer:
y < -1/4x -1
Step-by-step explanation:
The boundary line appears to go through the points (-4, 0) and (0, -1). This tells you it has a "rise" of -1 for a "run" of 4. The slope is ...
m = rise/run = -1/4
The y-intercept (b) is the point where the y-axis is crossed. The slope-intercept equation of the boundary line is ...
y = mx + b
y = -1/4x -1
__
The boundary line is dashed, so is not included in the solution set. The shading is below the line, so all y-values less than (but not equal to) the boundary line are in the solution set:
y < -1/4x -1
Solve for the unknown variable
4y-2=8-2y+4y
y=?
Step-by-step explanation:
I hope it helped and it is easy to understand i hope it was helpful
1)4y-2=8-2y+4y
=4y-2y+4y=8-2
2y +4y=8-2
6y+6
12
write your answer in simplest radical form
Answer:
[tex]8\sqrt{2}[/tex]
Step-by-step explanation:
Maybe this image can help you.
find area of shaded region
Answer:
The answer is 21.98. I just took area of the whole circle and subtracted it with the area of two circles in it
Answer:
21. 99
Step-by-step explanation:
[tex]s = \pi \times {r}^{2} \\ s1 = 3.14 \times 9 = 28.27 \\ s2 = 3.14 \times 1 = 3.14 \\ a = 28.27 - (3.14 \times 2) = 28.27 - 6.28 = 21.99[/tex]
look at the image to find the question
Answer:
yes, the volume = 16 ft^3
Solve the equation.
0.50x +0.45(50) = 48.5
x=?
Answer:
x=52 Here is y
Step-by-step explanation:
Write a word phrase for each algebraic expression.
13. n + 6
14. 5 - c
15. 11.5 + y
17. 3x + 10
16. x/4 - 17
18. 10x + 7z
Step-by-step explanation:
6 more than nc is subtracted from 5y more than 11.510 more than thrice of x17 less than x divided by 4The product of 7 and z is added to the product of 10 and x.Rotation 90° counterclockwise around the origin of the point (-8,1)
find the missing side. round your answer to the nearest tenth. PLEASE HURRY
Answer:
5.4
Step-by-step explanation:
cos(theta) = B/H
cos(75)=x/21, x=5.4
The bar graph shows the z-score results of four students on two different mathematics tests. The students took Test 1 and then, a month later, took Test 2. Which student had the lowest score on Test 2? Euan Felicia Dave Carla
Answer:
euan had lowest score on test 2
The student with lowest score on test 2 is Euan.
What is bar graph ?Bar graph is used for the graphical representation of data or quantities by using bars or strips.
Here,
The z-score results of four students on two different mathematics tests is represented by the given bar graph.
Calculating the scores of each students for the two tests respectively.
1) Carla
Test 1: 0.75
Test 2: -0.5
2) Dave
Test 1: -0.5
Test 2: 1
3) Euan
Test 1: 0.25
Test 2: -1
4) Felicia
Test 1: 1.25
Test 2: 1.5
Hence,
The student with lowest score on test 2 is Euan.
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I need help this is confusing to me
Answer:i think it is b not really sure
Step-by-step explanation:
Which function has a maximum with the same maximum value as
Answer:
Step-by-step explanation:
Consider the graph below, and identify the piecewise function that describes it.
Answer:
f(x)=-x when x belongs to (-infinity, 3)
f(x)=-2 when x belongs to [3, 6]
f(x)=2x-7 when x belongs to (6, infinity)
Write the place and Value of Each Number
27 210 What place is the selected digit in?
What is the value of the selected digit?
48,177 What place is the selected digit in?
What is the value of the selected digit?
A
62,774 What place is the selected digit in?
What is the value of the selected digit?
73,646 What place is the selected digit in?
What is the value of the selected digit
A
Answer:
C
Step-by-step explanation:
The answer pl shhaoksngausinxbbs pls
Answer:
D. 3
Step-by-step explanation:
A triangle can be defined as a two-dimensional shape that comprises three (3) sides, three (3) vertices and three (3) angles.
Simply stated, any polygon with three (3) lengths of sides is a triangle.
In Geometry, a triangle is considered to be the most important shape.
Generally, there are three (3) main types of triangle based on the length of their sides and these include;
I. Equilateral triangle: it has all of its three (3) sides and interior angles equal.
II. Isosceles triangle: it has two (2) of its sides equal in length and two (2) equal angles.
III. Scalene triangle: it has all of its three (3) sides and interior angles different in length and size respectively.
In Geometry, an acute angle can be defined as any angle that has its size less than ninety (90) degrees.
Hence, we can deduce that the greatest number of acute angles that a triangle can contain is three (3) because the sum of all the interior angles of a triangle is 180 degrees.
What percentages of participants in the study were American?
Tile is to be placed in an entryway, as shown below.
At $6.25 per square foot, how much does it cost to tile the entryway?
Calculate the area by using 2 rectangles:
13 x 5 = 65 square feet
5 x 4 = 20 square feet
Total area = 65 + 20 = 80 square feet.
Multiply price per square foot by total area:
6.25 x 80 = 500
Cost = $500
write your answer in simplest radical form
Answer:
x = 2 yd
Step-by-step explanation:
Angles of 45 degreees = two congruent legs
for the Pythagorean theorem
2x^2 = 8
x^2 = 4
x = 2
