1. Find the exact value of sin( a−B), given that sin a=−4/5 and cos B=12/13, with a in quadrant III and B in quadrant IV.
2. Find all real numbers in the interval [0,2pi) that satisfy the equation.
3sec^2 x tan x =4tan x
3. Simplify the following trigonometric expressions, using identities as needed:
sin(x)/1−cos(x) + 1−cos(x)/sin(x)
Answers
(1) Recall that
sin(x - y) = sin(x) cos(y) - cos(x) sin(y)
sin²(x) + cos²(x) = 1
Given that α lies in the third quadrant, and β lies in the fourth quadrant, we expect to have
• sin(α) < 0 and cos(α) < 0
• sin(β) < 0 and cos(β) > 0
Solve for cos(α) and sin(β) :
cos(α) = -√(1 - sin²(α)) = -3/5
sin(β) = -√(1 - cos²(β)) = -5/13
Then
sin(α - β) = sin(α) cos(β) - cos(α) sin(β) = (-4/5) (12/13) - (-3/5) (-5/13)
==> sin(α - β) = -63/65
(2) In the second identity listed above, multiplying through both sides by 1/cos²(x) gives another identity,
sin²(x)/cos²(x) + cos²(x)/cos²(x) = 1/cos²(x)
==> tan²(x) + 1 = sec²(x)
Rewrite the equation as
3 sec²(x) tan(x) = 4 tan(x)
3 (tan²(x) + 1) tan(x) = 4 tan(x)
3 tan³(x) + 3 tan(x) = 4 tan(x)
3 tan³(x) - tan(x) = 0
tan(x) (3 tan²(x) - 1) = 0
Solve for x :
tan(x) = 0 or 3 tan²(x) - 1 = 0
tan(x) = 0 or tan²(x) = 1/3
tan(x) = 0 or tan(x) = ±√(1/3)
x = arctan(0) + nπ or x = arctan(1/√3) + nπ or x = arctan(-1/√3) + nπ
x = nπ or x = π/6 + nπ or x = -π/6 + nπ
where n is any integer. In the interval [0, 2π), we get the solutions
x = 0, π/6, 5π/6, π, 7π/6, 11π/6
(3) You only need to rewrite the first term:
[tex]\dfrac{\sin(x)}{1-\cos(x)} \times \dfrac{1+\cos(x)}{1+\cos(x)} = \dfrac{\sin(x)(1+\cos(x))}{1-\cos^2(x)} = \dfrac{\sin(x)(1+\cos(x)}{\sin^2(x)} = \dfrac{1+\cos(x)}{\sin(x)}[/tex]
Then
[tex]\dfrac{\sin(x)}{1-\cos(x)}+\dfrac{1-\cos(x)}{\sin(x)} = \dfrac{1+\cos(x)+1-\cos(x)}{\sin(x)}=\dfrac2{\sin(x)}[/tex]
Related Questions
Assume that the helium porosity (in percentage) of coal samples taken from any particular seam is normally distributed with true standard deviation 0.74. (a) Compute a 95% CI for the true average porosity of a certain seam if the average porosity for 19 specimens from the seam was 4.85. (Round your answers to
Answers
Answer:
The answer is "(4.518, 5.182)"
Step-by-step explanation:
[tex]\sigma = 0.74[/tex]
The aveage porosity for a sample of [tex]n = 19[/tex] specimens is
[tex]\bar{x}=4.85[/tex]
Thus, the[tex]95\%[/tex] confidence interval for the true mean is
[tex]=\bar{x}\pm Z_{\frac{0.05}{2}} \frac{\sigma}{\sqrt{n}}\\\\=4.85\pm 1.96 \frac{0.74}{\sqrt{19}}\\\\=4.85\pm 0.332\\\\=(4.518, 5.182)[/tex]
Therefore, one can state that the true average porosity will lie between 4.518 and 5.182 with the 95\% confidence.
A son is 8 years old. his father is 5 times as old. How old will the father be when he is twice as old as his son?
Answers
two cars started to move towards each other at the same time. the speed of the first car was twice the speed of the second car. they met in two hours. if the distance traveled altogether was 300 km find the rates of the cars.
Answers
Answer:
Step-by-step explanation:
Let v be the speed of the slower car
2v is the speed of the faster car
In 2 hrs, the slower car travels a distance of
2 hr(v km/hr) = 2v km
In 2 hrs, the faster car travels a distance of
2 hr(2v km/hr) = 4v km
2v + 4v = 300
6v = 300
v = 50 km/hr
2v = 100 km/hr
whats the value of 5 in the product of 6,541 x 100
Answers
Answer:
50,000
Step-by-step explanation:
The product would be 654,100. Replace the other numbers to find the value of 5. The value of 5 is 050,000 or 50,000.
I hope this helps!
Water is flowing into a tank at a rate of 20 cm3/min. At the start, there is 250 cm3 of water in the tank.
(i) How much water will be in the tank after 30 minutes?
(ii) Find the time when there is 1210 cm3 of water in the tank.
Answers
Answer:
i) 410 cm³
ii) 48 min
Step-by-step explanation:
we start with 250 cm³.
and then we fill in 20 cm³ per minute.
i)
after 30 minutes we have
250 + 8×20 = 250 + 160 = 410 cm³
ii)
how long (how many minutes) does it take to reach 1210 cm³ in the tank ?
well, first we subtract the start amount (250).
and then we see how often 20 cm³ will "fit" into the remainder. and then we know how many minutes the water has to run.
1210 - 250 = 960 cm³
so, the incoming water needs to reach 960 cm³ to have a total of 1210 cm³.
and
960 cm³ / (20 cm³ / min) = 960 cm³ min / 20 cm³ =
= 960 min / 20 = 48 min
find the intercept and graph the following linear equations: 2x+y=1
plz include x and y intercepts
Answers
Answer:
2(1)+y =1 for × intercept
2x+(1)=1 for y intercept
please help answer question
Answers
Answer:
Mark me brainlist please please please please
Answer:
Step-by-step explanation:
Determine whether the series is absolutely convergent, conditionally convergent, or divergent.
[infinity]Σ n =1 (-1)^n - 1/n√n
Answers
Answer: hello your question is poorly written attached below is the complete question
answer:
The series is absolutely convergent
Step-by-step explanation:
To determine whether the series is absolutely or conditionally convergent or divergent. apply the Root Test
The series is absolutely convergent
attached below is the solution
The manager of a movie theater is standing outside the theater complex one evening. He will be asking the moviegoers questions.
Which questions can the manager ask that will result in discrete quantitative data? Check all that apply.
What movie did you just see?
What genre of movie is your favorite?
How much did you spend at the movies today?
Did you order anything from the concession stand?
Answers
Answer:
It's How much did you spend at the movies today?
Step-by-step explanation:
The question can the manager asks "How much did you spend at the movies today?". Then the correct option is C.
What is discrete quantitative data?A discrete quantitative parameter has a clear mathematical explanation but could only take certain integer values (instead of every value in intervals).
The manager of a movie theater is standing outside the theater complex one evening.
He will be asking the moviegoers questions.
Then the questions can the manager ask that will result in discrete quantitative data will be
How much did you spend at the movies today?
The question can the manager asks "How much did you spend at the movies today?"
Then the correct option is C.
More about the discrete quantitative data link is given below.
https://brainly.com/question/12831013
#SPJ2
Tuition. The tuition at a community college increased from $2,500 to $2,650 per semester. What was the percent of increase in the tuition?
Answers
Answer:
6 percent increase
Step-by-step explanation:
2650 divided by 2500 gives you 1.06 which means if 2500 is 100 percent 2650 would be 106 percent so the answer is a 6 percent increase
Answer:
6%
Step-by-step explanation:
another way of doing this type of calculation is...
NEW-OLD = 2650-2500 = 150 = .06 = 6%
OLD 2500 2500
Which undefined geometric term is described as a two-dimensional set of points that has no beginning or end
Answers
Answer:
plane
Step-by-step explanation:
The two-dimensional set of points that has no beginning or end is described by the undefined geometric term is plane.
Find the Z scores for which 5% of the distributions area lies between negative Z & Z
Answers
Answer:
0.475: Z = -0.062706778
0.525: Z = 0.062706778
Step-by-step explanation:
(3x - 2)^5 =(3x - 2)^2
Answers
Answer:
x=3/2,1
Step-by-step explanation:Given
(3x-2)ˆ5-(3x-2)ˆ2=0
(3x-2)ˆ3(3x-2)ˆ2-(3x-2)ˆ2=0
(3x-2)ˆ2{(3x-2)ˆ3-1}=0
(3x-2)ˆ2=0 Or (3x-2)ˆ3-1=0
3x-2=0 Or(3x-2)ˆ3=1
x=3/2 Or 3x-2=1, x=1
A local church holds an annual raffle to raise money for a new roof. They sell only 500 tickets at $50 each. This year's prizes include: $3,000 in cash, four $100 Amazon gift cards, and two $75 Visa gift cards. You buy one ticket. What is your mathematical expectation for this game
Answers
Answer:
The expectation for an event with outcomes:
{x₁, x₂, ..., xₙ}
Each one with probability:
{p₁, p₂, ..., pₙ}
Is:
Ev = x₁*p₁ + ... + xₙ*pₙ
There are 500 tickets sold.
1 of these, wins $3,000 (this is the event x₁)
4 of these, wins $100 (this is the event x₂)
2 of these, wins $75 (this is the event x₃)
The others do not have a prize.
So the probability of winning the $3000 is equal to the quotient between the number of tickets with that prize (1) and the total number of tickets (500)
p₁ = 1/500
Similarly, the probability of winning $100 will be:
p₂ = 4/500
And for the $75 prize:
p₃ = 2/500
Then the probability of not winning is:
p₄ = 493/500
Then the expected value for a single ticket is:
Ev = $0*493/500 + $75*2/500 + $100*4/500 + $3000*1/500
Ev = $7.1
If you take in account that you pay $50 for the ticket, the actual expectation should be:
E = $7.10 - $50 = -$42.90
7. Solve for x: x/6 - y/3 = 1
Please give steps! ❤️
Answers
[tex]\\ \sf\longmapsto \frac{x}{6} - \frac{y}{3} = 1 \\ \\ \sf\longmapsto \frac{x - 2y}{6} = 1 \\ \\ \sf\longmapsto x - 2y = 6 \\ \\ \sf\longmapsto x = 6 + 2y[/tex]
find two ordered pairs for x-4y=2
Answers
Answer:
x-4y=2 can be written as y=(x-2)/4
(2,0) when x=2, y=0 and (6,1) when x=6, y=1
E
Homework: Practice
Exam 3
Question 7
Find the standard deviation for the group of data items.
14, 15, 16, 16, 17, 18
The standard deviation is
(Simplify your answer. Round to two decimal places as needed.)
9
Answers
Answer:
Step-by-step explanation:
What is the solution to this system of equations?
a - b + c = -6
b - c = 5
2a - 2c = 4
A) 2
B) -1
C) -3
D) 1
Answers
(-1;2;-3)
а, b, c
~~~~~~
If one big rectangle represents one whole what fraction of area is shaded gold in the two rectangle
Answers
Answer:
15/8
Step-by-step explanation:
one big rectangle is 1 or 8/8 and the other is 7 out of 8, therefore we have 8/8+7/8 = 15/8.
Write the standard form of the equation of the circle with radius 3 and center (−4,−10)
Answers
Answer:
(x + 4)² + (y + 10)² = 9
Step-by-step explanation:
The standard equation of a circle is written as seen below
(x - h)² + (y - k)² = r²
Where (h,k) is at the center and r is the radius
We want to find the standard equation of a circle that has a radius of 3 and a center at (-4,-10)
Remember r = radius so r = 3
and (h,k) is at center so h = -4 and k = -10
Now to find the standard equation of the circle we simply plug in the values of the variables (h,k and r) into the standard equation of a circle formula.
Equation of a circle: (x - h)² + (y - k)² = r²
r = 3, h = -4 and k = -10
Plug in values
(x - (-4))² + (y - (-10))² = 3²
Simplify
(x + 4)² + (y + 10)² = 9
And we are done!
What is the inverse of the function g (x) = 5 (x - 2)
Answers
Answer:
g − 1 ( x ) = x/ 5 + 2
Step-by-step explanation:
See the pic for solutions :)
A test is worth 30 points. Multiple-choice questions are worth 2 point and short-answer questions are worth 3 points. If the test has 13 questions, how many multiple-choice questions are there?
Answers
Equations:
2x + 3y = 30
x + y = 13
Plug them in:
2(9) + 3(4) = 30
9 + 4 = 13
2x9=18, 3x4=12, 12+18=30 points, 9+4=13 questions
What is the volume of a pyramid below?
600 cm^3
750 cm^3
900 cm^3
1800 cm^3
Answers
Answer: 600 cm³
Step-by-step explanation:
Volume of square pyramid = (1/3) · b² · h
b = base edge length = 10 cmh = height = 18 cmTherefore, the volume can be calculated as
[tex]\frac{1}{3} *10^{2}*18=\frac{1}{3}*100*18=\frac{1}{3}*1800=\frac{1800}{3}=600[/tex]
Answer
900
Step-by-step explanation:
it is pyramid and finding its volume we use the 3 components that is length, with and the height
1/2 base x width x height
5 x 18 x 10 = 900cm³
HELP ME PLEASE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Answers
9514 1404 393
Answer:
D. 72 heads in 100 flips
Step-by-step explanation:
A probability calculator will tell you the probabilities of the given outcome with a fair coin are ...
A: 0.0625
B: 0.04395
C: 0.15498
D: 3.9×10^-6
__
It is "improbable" that a fair coin will give 72 heads in 100 flips. So, it is reasonable to assume the coin is not fair if that is the result.
Adam runs 13 miles in 143 minutes. How many minutes does it take him to run one mile? Adam runs at a rate of minutes per mile.
Answers
Answer:
Adam runs at a rate of 11 minutes per mile.
Step-by-step explanation:
Take 143 minutes and divide by 13 miles and you will get the answer of 11 minutes.
PLEASE MARK ME BRAINEIST.
Answer:
it would take him 11 minuets to run a mile
Step-by-step
143 divided by 13 is 11 which means each mile takes 11
you can also check the answer by multiplying 13 times 11 which is 143
Solve for x.
2(3x - 7) = 16
Simplify your answer as much as possible.
X =
Answers
Answer:
x = 5
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightEquality Properties
Multiplication Property of Equality Division Property of Equality Addition Property of Equality Subtraction Property of EqualityStep-by-step explanation:
Step 1: Define
Identify
2(3x - 7) = 16
Step 2: Solve for x
[Division Property of Equality] Divide 2 on both sides: 3x - 7 = 8[Addition Property of Equality] Add 7 on both sides: 3x = 15[Division Property of Equality] Divide 3 on both sides: x = 5Answer:
X=5
Step-by-step explanation:
divide by 2 on both sides first then you have
3x-7 = 8
take 7 to the other side so that you have an X factor on one side, thus
3x =15
then divide by 3 to remain with X
X = 5
One time Maria took 27 minutes to walk 1.8km to school. She left home at 07:48 . Write down the time Maria arrived at school
Answers
Answer:
8:15
Step-by-step explanation:
Which expression is equivalent to: 16x - 16
4(2x - 2)
4(4x - 16)
4(4x - 4)
Answers
Answer:
4(4x-16)
Step-by-step explanation:
If you like my answer than please mark me as brainliest
Using the distributive property you would take the 4 outside of the parentheses, and multiply it by the 4x and then by the -4 inside the parentheses. 4•4x=16x. 4•-4=16 (remembering that a negative times a positive is still a negative)
Question 3 (5 points)
Draw a right isosceles triangle.
Answers
Answer:
Step-by-step explanation:
Vẽ góc vuông. - Trên hai canh góc vuô dùng thước thước có chia khoảng vẽ hai đoạn thẳng bằng nhau có chung một điểm và nối hai điểm còn lại.
The Demand function for a product is given by:
D(q) = - 0.0003q^2 - 0.04q + 23.56
where q is the number of units sold and D(q) is the corresponding price per unit, in dollars. What is the average rate of change of Demand between 40 and 175 units sold?
Answers
Answer:
The average rate of change of Demand between 40 and 175 units sold is of -0.1045.
Step-by-step explanation:
Average rate of change:
The average rate of a function f(x) in an interval [a,b] is given by:
[tex]A = \frac{f(b) - f(a)}{b - a}[/tex]
In this question:
[tex]D(q) = -0.0003q^2 - 0.04q + 23.56[/tex]
What is the average rate of change of Demand between 40 and 175 units sold?
[tex]a = 40, b = 175[/tex]. So
[tex]D(40) = -0.0003*40^2 - 0.04*40 + 23.56 = 21.48[/tex]
[tex]D(175) = -0.0003*175^2 - 0.04*175 + 23.56 = 7.3725[/tex]
So
[tex]A = \frac{f(b) - f(a)}{b - a} = \frac{7.3725 - 21.48}{175 - 40} = -0.1045[/tex]
The average rate of change of Demand between 40 and 175 units sold is of -0.1045.
