Find the exact values of the six trigonometric functions at “a” given cos(2a) = - 4/5 and a is
in the 2nd quadrant.
If a is in the second quadrant, then cos(a) < 0 and sin(a) > 0.
Recall the double angle identity for cosine:
cos(2a) = 2 cos²(a) - 1 = 1 - 2 sin²(a)
It follows that
2 cos²(a) - 1 = -4/5 ==> cos²(a) = 1/10 ==> cos(a) = -1/√10
1 - 2 sin²(a) = -4/5 ==> sin²(a) = 9/10 ==> sin(a) = 3/√10
Then we find
1/cos(a) = sec(a) = -√10
1/sin(a) = csc(a) = √10/3
sin(a)/cos(a) = tan(a) = -3
1/tan(a) = cot(a) = -1/3
Test for symmetry and then graph the polar equation.
r=3−5sinθ
Answer:
Symmetric with respect to the x-axis
Symmetric with respect to the y-axis
Symmetric with respect to the origin
2) If licorice cost $6.59 a pound, how much would it cost to buy a quarter pound of licoric
(Hint: Convert the mixed fraction to an improper fraction or decimal and multiply by th
quantity required)
Answer:
$1.65
Step-by-step explanation:
[tex]6.59*.25=1.65[/tex]or
[tex]6.59*\frac{1}{4} =1.65[/tex]Solve the following equation by first writing the equation in the form a x squared = c:
3 a squared minus 21 = 27
A. a = 4
B. a = plus-or-minus 4
C. a = plus-or-minus 16
D. a = 16
9514 1404 393
Answer:
B. a = plus-or-minus 4
Step-by-step explanation:
3a² -21 = 27 . . . . . . . given
3a² = 48 . . . . . . . . . . add 21 to both sides (desired form)
a² = 16 . . . . . . . . . . . divide both sides by 3
a = ±4 . . . . . . . take the square root
14. In a statistics class with 15 males and 13 females, five students are selected to put problems on the board. What is the probability that:
a. 3 females and 2 males are selected? b.all five students selected are males? c. all five students selected are females? d.at least one male is selected?
Answer:
a) 0.3056 = 30.56% probability that 3 females and 2 males are selected.
b) 0.0306 = 3.06% probability that all five students selected are males.
c) 0.0131 = 1.31% probability that all five students selected are females.
d) 0.9869 = 98.69% probability that at least one male is selected.
Step-by-step explanation:
The students are chosen from the sample without replacement, which means that the hypergeometric distribution is used to solve this question.
Hypergeometric distribution:
The probability of x successes is given by the following formula:
[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}[/tex]
In which:
x is the number of successes.
N is the size of the population.
n is the size of the sample.
k is the total number of desired outcomes.
In this question:
15 + 13 = 28 students, which means that [tex]N = 28[/tex]
5 are selected, which means that [tex]n = 5[/tex]
13 females, which means that [tex]k = 13[/tex]
a. 3 females and 2 males are selected?
3 females, so this is P(X = 3).
[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}[/tex]
[tex]P(X = 3) = h(3,28,5,13) = \frac{C_{13,3}*C_{15,2}}{C_{28,5}} = 0.3056[/tex]
0.3056 = 30.56% probability that 3 females and 2 males are selected.
b.all five students selected are males?
0 females, so this is P(X = 0).
[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}[/tex]
[tex]P(X = 0) = h(0,28,5,13) = \frac{C_{13,0}*C_{15,5}}{C_{28,5}} = 0.0306[/tex]
0.0306 = 3.06% probability that all five students selected are males.
c. all five students selected are females?
This is P(X = 5). So
[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}[/tex]
[tex]P(X = 5) = h(5,28,5,13) = \frac{C_{13,5}*C_{15,0}}{C_{28,5}} = 0.0131[/tex]
0.0131 = 1.31% probability that all five students selected are females.
d.at least one male is selected?
Less than five females, so:
[tex]P(X < 5) = 1 - P(X = 5) = 1 - 0.0131 = 0.9869[/tex]
0.9869 = 98.69% probability that at least one male is selected.
In a poll, adults in a region were asked about their online vs. in-store clothes shopping. One finding was that % of respondents never clothes-shop online. Find and interpret a % confidence interval for the proportion of all adults in the region who never clothes-shop online.
The question is incomplete. The complete question is :
In a poll, 1100 adults in a region were asked about their online vs. in-store clothes shopping. One finding was that 43% of respondents never clothes-shop online. Find and interpret a 95% confidence interval for the proportion of all adults in the region who never clothes-shop online.
Solution :
95% confidence interval for p is :
[tex]$\hat p - Z_{\alpha/2}\times \sqrt{\frac{\hat p(1-\hat p)}{n}} < p < \hat p + Z_{\alpha/2}\times \sqrt{\frac{\hat p(1-\hat p)}{n}}$[/tex]
[tex]$0.43 - 1.96\times \sqrt{\frac{0.43(1-0.43)}{1100}} < p < 0.43 + 1.96\times \sqrt{\frac{0.43(1-0.43)}{1100}}$[/tex]
0.401 < p < 0.459
Therefore, 95% confidence interval is from 0.401 to 0.459
Jeff has 20 coins. 2/5 of them are quarters. How many quarters does he have? How many coins are not quarters?
If the total income generated from Gasoline for AER was $408 millions, how much would be the cost for a barrel of gasoline
The square pyramid shown below has a base with sides of 10 units. The slant height of the pyramid is 8 units. What is the vertical height, h?
Round your answer to the nearest tenth.
Answer:
h = 6.2 units
Step-by-step explanation:
Given triangle ABC is a right triangle with the measures of the two sides,
BC = [tex]\frac{10}{2}[/tex] = 5 units
AC = 8 units
By applying Pythagoras theorem in the given triangle,
AC² = AB² + BC²
8² = AB² + 5²
AB² = 64 - 25
AB = √39
AB = 6.24 units
AB ≈ 6.2 units
Which of the following is the vertical asymptote for the graph below?
Answer:
C
Step-by-step explanation:
Vertical asymptotes are always in the form x = ?
If you look at the dotted line, it lands on 2. Because it's a vertical line, the asymptote is going to be x = 2
Remember the dataset of alligators which was about the length and weight of several aligators in Florida. The variable X is the length of aligator and the Y variable is the weight of them. A researcher decided to use decision tree and designed two steps: X<4, X>4. What is the name of this method of splitting?A. Multi-way splitting.B. Entropy classification.C. Binary splitting.D. Gini index.
Answer:
A. multi-way split.
Step-by-step explanation:
Multi way split consists of internal at decision tree branches. Gini index measures probability of impurity in the random variables chosen. Entropy is measure of uncertainty in the sample selected. Binary splitting is used to speed up numerical evaluation.
Help with solving this Functions problem
Answer:
See answers below
Step-by-step explanation:
Given the following functions:
r(x) = x - 6
s(x) = 2x²
r(s(x)) = r(2x²)
Replacing x with 2x² in r(x) will give;
r(2x²) = 2x² - 6
r(s(x)) = 2x² - 6
(r-s)(x) = r(x) - s(x)
(r-s)(x) = x - 6 - 2x²
Rearrange
(r-s)(x) = - 2x²+x-6
(r+s)(x) = r(x) + s(x)
(r-s)(x) = x - 6 + 2x²
Rearrange
(r-s)(x) = 2x²+x-6
A human resources office is working to implement an increase in starting salaries for new
administrative secretaries and faculty at a community college. An administrative secretary
starts at $28,000 and new faculty receive $40,000. The college would like to determine the
percentage increase to allocate to each group, given that the college will be hiring 8
secretaries and 7 faculty in the upcoming academic year. The college has at most $5,000 to
put towards raises. What should the percentage increase be for each group?
Answer:
Step-by-step explanation :
Let % increase in administrative secretary be = x
Let % increase in new faculty receive be = y
Administrative secretary salary = 28,000
New faculty receive Salary = 40,000
(8)*(x/100)* (28000) + (7)*(y/100)*(40000) = 5,000
2240x +2800 y = 5,000
224x +280 y = 500
56x +70y = 125
Therefore, x and y should be chosen such that it satisfy the above equation.
PLEASE HELPPP THIS IS DUE ASAPPPP!!!!!!!!!!!!!! WILL GIVE BRAINLIEST
Answer:
I think the answer is 5/6
Step-by-step explanation:
There are three even numbers and two uneven numbers less than four. Therefore, on a standard die, the.probability of Rollin a number that is even or less than for is 5/6.
5(6t-3)=5t+35
find the value of t
Answer:
t = 2
Step-by-step explanation:
5(6t-3)=5t+35
Step 1 distribute the 5 by multiplying 5 to what is inside of the parenthesis
5(6t) - 5(3) = 5t + 35
Outcome: 30t - 15 = 5t + 35
Step 2 add 15 to both sides
30t - 15 + 15 = 5t + 35 + 15
Outcome: 30t = 5t + 50
Step 3 subtract 5t from both sides
30t - 5t = 5t - 5t + 50
Outcome: 25t = 50
Step 4 divide both sides by 25
25t/25 = 50 we're left with t = 2
Simplify the following expression: (4x2)2 • (3x3)3
Answer:
432x^13
Step-by-step explanation:
(4x^2)^2 • (3x^3)^3
We know that a^b^c = a^(b*c)
4^2 x^2^2 * 3^3 x^3^3
16 x^4 * 27 x^9
We know that a^b ^ a^c = a^(b+c)
16*27 x^(4+9)
432x^13
Answer:
432x¹³
Step-by-step explanation:
( 4x² ) ² • ( 3x³ ) ²
( 16x²)² • ( 27x³)²
[tex]16 x{}^{2 \times 2} \times 6 {}^{3 \times 3 } \\ 16x {}^{4} \times27 {}^{9} [/tex]
[tex](16 \times 27)x {}^{4 + 9} [/tex]
432x¹³
PLEASE HELP ME ASAP!!!
The answer is 4 because the frequency is the number of cycles completed in one interval. Typically, the interval given is 2π. Here, you can count the cycles and get 4.
what's the radius of 16x^2+16y^2=1 With a center of (0,0) ?
Answer:
The center is (0,0) and the radius is 1/4
Step-by-step explanation:
The formula for a circle is
(x-h)^2 + (y-k)^2 = r^2 where (h,k) is the center and r is the radius
16x^2+16y^2=1
Divide by 16
x^2+y^2=1/16
x^2 + y^2 = (1/4) ^2
(x-0)^2 + (y-0)^2 = (1/4) ^2
The center is (0,0) and the radius is 1/4
Choose the function whose graph is given by:
OA.y= cos(2x)
OB.y= cos(1/2x)
OC.y= cos(4x)
D. y = cos(1/4x)
Using translation concepts, it is found that the function whose graph is given is:
A. y= cos(2x)
What is a translation?A translation is represented by a change in the function graph, according to operations such as multiplication or sum/subtraction in it's definition.
The original cosine function has period of [tex]2\pi[/tex], and in this problem, the function has a period of [tex]\pi[/tex], hence the domain was multiplied by 2, which means that option A is correct.
More can be learned about translation concepts at https://brainly.com/question/4521517
#SPJ1
Please please help me i can’t figure this out .. ernest's friend rolls a six-sided number cube and lands on square 8. She asks Ernest to guess what number she rolled. He guesses that she rolled a 3. She says he's wrong.
ernest wonders if she could have rolled a number other than 3. Use a mapping diagram to help guess what number she rolled.
If she would have rolled
Create a Mapping Diagram
When playing this game, the square you land on during the first turn depends on the number you roll. You can write this as a function: SQUARE(number), or S(n). For example, if you roll a 2, you end up on square 2 (when you land on 3 you move back a space). So S(2) = 2.
1. Describe the possible inputs of S(n) using words. (2 points: 1 point for the description, 1 point for the list of numbers)
2. Describe the possible outputs of S(n) using words. (1 point)
3. Draw a mapping diagram for S(n) that maps all the possible inputs and outputs for a player's first turn. Note that the player should begin on square 1. (6 points: 3 points for the inputs and outputs, and 3 points for the mapping)
4. In the mapping diagram you created, what numbers are in the domain of S(n)? Explain what this means. (2 points: 1 point for the domain, 1 point for the explanation)
5. What numbers are in the range of S(n)? Explain what this means. (2 points: 1 point for the range, 1 point for the explanation)
Evaluate the Conjecture
6. Based on the mapping diagram, is it possible that the player rolled a number other than 3 to land on square 8? If so, which number or numbers? Explain your answer. (2 points: 1 point for the answer, and 1 point for the explanation)
Defining Functions
7. Does the mapping diagram you created for S(n) for the first turn of the game represent a function? Why or why not? (2 points: 1 point for the answer, and 1 point for the explanation)
Step-by-step explanation:
1. The inputs are the dice values. Since the cube is six sided, the possible. values are (1,2,3,4,5,6).
2. The outputs values are points if we roll the number. If we land in a special space, we must respect that rule so our outputs are
(2,2,8,5,6,8).
3. I cant show a mapping diagram on brainly. Draw a mapping diagram and make sure to connect the x values and y values of the following.Also make sure to start on square 1.
1 corresponds with 22 corresponds with 23 corresponds with 84 corresponds with 55 corresponds with 66 corresponds with 84. The domain of the function is the same as the input. The dice values, 1,2,3,4,5,6
5.The range are the. values that occur if we roll the number about square 1.
2,2,8,5,6,8
6. No, the player could have rolled 3 and landed on 8. The player also could have rolled 6.
7. Yes, every one x value corresponds with one y value.
F(4) =
If g(x) = 2, x=
An
Step-by-step explon:
Use the figure to find u.
Answer:
u = 2
Step-by-step explanation:
Since this is a right triangle, we can use trig functions
cos theta = adj side / hypotenuse
cos 45 = sqrt(2) / u
u cos 45 = sqrt(2)
u = sqrt(2) / cos 45
u = sqrt(2) / 1/ sqrt(2)
u = sqrt(2) * sqrt(2)
u =2
u=2
Answer:
Solution given:
Relationship between base and hypotenuse is given by cos angle.Cos 45°=base/hypotenuse
[tex]\frac{1}{\sqrt{2}}=\frac{\sqrt{2}}{u}[/tex]
doing crisscrossed multiplication
[tex]\sqrt{2}*\sqrt{2}=1*u[/tex]
u=2
If 6,000 dollars in aacount after 3 years after account earn 6% interest yearly how much do you deposit today.
I need the help for this quick app anyone can help
A county office gets an average of 10 calls in a 2 hour time period. What is the probability that the county office will get more than 0 calls in a 15 minute period? Round your answer to three decimal places.
Answer:
0.713 = 71.3% probability that the county office will get more than 0 calls in a 15 minute period.
Step-by-step explanation:
We have the mean during a time-period, which means that the Poisson distribution is used to solve this question.
In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:
[tex]P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}[/tex]
In which
x is the number of sucesses
e = 2.71828 is the Euler number
[tex]\mu[/tex] is the mean in the given interval.
A county office gets an average of 10 calls in a 2 hour time period.
10 calls each 120 minutes, which means that the mean for n minutes is:
[tex]\mu = \frac{10n}{120} = \frac{n}{12}[/tex]
15 minute period:
This means that [tex]n = 15, \mu = \frac{15}{12} = 1.25[/tex]
What is the probability that the county office will get more than 0 calls in a 15 minute period?
This is:
[tex]P(X > 0) = 1 - P(X = 0)[/tex]
In which
[tex]P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}[/tex]
[tex]P(X = 0) = \frac{e^{-1.25}*1.25^{0}}{(0)!} = 0.287[/tex]
So
[tex]P(X > 0) = 1 - P(X = 0) = 1 - 0.287 = 0.713[/tex]
0.713 = 71.3% probability that the county office will get more than 0 calls in a 15 minute period.
60 units needed, 14 units per case. What is the number of cases and the number of additional units?
Answer:
5 cases
10 additional units
Step-by-step explanation:
Given that :
Total number of units needed = 60 units
Total number of units per case = 14
Hence, the total number of cases required will be :
Number of units needed / number of units per case
Number of cases required = 60 / 14 = 4.285 (this means that 5 cases are required as 4 cases won't be up to 60 units)
With 5 cases, we have exceeded the required units needed :
Additional units will be : (14 * 5) - 60
Additional units = 70 - 60 = 10 units
help with numer 5 please. thank you
Answer:
See Below.
Step-by-step explanation:
We are given that:
[tex]\displaystyle I = I_0 e^{-kt}[/tex]
Where I₀ and k are constants.
And we want to prove that:
[tex]\displaystyle \frac{dI}{dt}+kI=0[/tex]
From the original equation, take the derivative of both sides with respect to t. Hence:
[tex]\displaystyle \frac{d}{dt}\left[I\right] = \frac{d}{dt}\left[I_0e^{-kt}\right][/tex]
Differentiate. Since I₀ is a constant:
[tex]\displaystyle \frac{dI}{dt} = I_0\left(\frac{d}{dt}\left[ e^{-kt}\right]\right)[/tex]
Using the chain rule:
[tex]\displaystyle \frac{dI}{dt} = I_0\left(-ke^{-kt}\right) = -kI_0e^{-kt}[/tex]
We have:
[tex]\displaystyle \frac{dI}{dt}+kI=0[/tex]
Substitute:
[tex]\displaystyle \left(-kI_0e^{-kt}\right) + k\left(I_0e^{-kt}\right) = 0[/tex]
Distribute and simplify:
[tex]\displaystyle -kI_0e^{-kt} + kI_0e^{-kt} = 0 \stackrel{\checkmark}{=}0[/tex]
Hence proven.
Question
Elvira and Aletheia live 3.2 miles apart on the same street. They are in a study group that meets at a coffee shop between their houses. It took Elvira 1/2 hour and Aletheia 2/3 hour to walk to the coffee shop. Find both women's walking speeds.
Missing from the question
Aletheia's speed is 0.6 miles per hour slower than Elvira's speed.
Answer:
[tex]s_E = 3.0[/tex]
[tex]s_A = 2.4[/tex]
Step-by-step explanation:
Given
[tex]d = 3.2m[/tex] -- distance
[tex]t_E = 1/2[/tex] --- Elvira time
[tex]t_A = 2/3[/tex] --- Aletheia time
[tex]s_E - s_A = 0.6[/tex] --- the relationship between their speeds
Required
Their walking speed
Distance (d) is calculated as:
[tex]d = speed * time[/tex]
For Elvira, we have:
[tex]d_E = s_E * 1/2[/tex]
For Aletheia, we have:
[tex]d_A = s_A * 2/3[/tex]
So, we have:
[tex]d_E + d_A = d[/tex] --- total distance
This gives:
[tex]s_E * 1/2 + s_A * 2/3 = 3.2[/tex]
Recall that:
[tex]s_E - s_A = 0.6[/tex]
Make sE the subject
[tex]s_E = 0.6+s_A[/tex]
Substitute [tex]s_E = 0.6+s_A[/tex] in [tex]s_E * 1/2 + s_A * 2/3 = 3.2[/tex]
[tex](0.6+s_A)* 1/2 + s_A * 2/3 = 3.2[/tex]
[tex]0.3+1/2s_A + 2/3s_A = 3.2[/tex]
Collect like terms
[tex]1/2s_A + 2/3s_A = 3.2-0.3[/tex]
[tex]1/2s_A + 2/3s_A = 2.9[/tex]
Express all as decimal
[tex]0.5s_A + 0.7s_A= 2.9[/tex]
[tex]1.2s_A= 2.9[/tex]
Divide both sides by 1.2
[tex]s_A = 2.4[/tex]
Recall that:
[tex]s_E = 0.6+s_A[/tex]
So, we have:
[tex]s_E = 0.6+2.4[/tex]
[tex]s_E = 3.0[/tex]
An alarm clock is slow. It falls behind 4 minutes every 24 hours. If the clock was showing the correct time at 6:00 this morning, how many seconds ahead was the clock at 10:00 last night?
Answer:
80 Seconds
I dont really want to type the whole thing out, just think about it again, or go to a tutor website, you should be able to get it, you have to use these, multiplication of three numbers, and multiplication and division by factorization of numbers.
A paper factory makes cardboard sheets like the one shown below. If the area of each sheet is given by the expression 6x ^ 2 + 7x + 2, what are the dimensions of each sheet of cardboard?
Answer:
(3x+2) by (2x+1)
Step-by-step explanation:
A cardboard is a rectangle, and has two dimensions. Given a quadratic equation, you should find a way to split it in two.
The easiest way to do so is through factoring. (There are many ways to do this, take a look at the plethora of sources offered on the internet.)
When the expression 6x^2 + 7x + 2 is factored, it is (3x+2)(2x+1). Hence, these are your dimensions.
Please help out would really appreciate it
Answer:
Step-by-step explanation:
1. Apply the Pythagoras theorem to determine the value of x, we have;
[tex]/Hyp/^{2}[/tex] = [tex]/Adj 1/^{2}[/tex] + [tex]/Adj 2/^{2}[/tex]
[tex]x^{2}[/tex] = [tex]15^{2}[/tex] + [tex]8^{2}[/tex]
= 289
x = [tex]\sqrt{289}[/tex]
x = 17
2. Trigonometric ratios of <D.
i. Sin <D = [tex]\frac{opposite}{hypotenuse}[/tex]
= [tex]\frac{8}{17}[/tex]
ii. Cos <D = [tex]\frac{Adjacent}{Hypotenuse}[/tex]
= [tex]\frac{15}{17}[/tex]
iii. Tan <D = [tex]\frac{Opposite}{Adjacent}[/tex]
= [tex]\frac{8}{15}[/tex]
3. Trigonometric ratios of <F.
i. Sin <F = [tex]\frac{opposite}{hypotenuse}[/tex]
= [tex]\frac{15}{17}[/tex]
ii. Cos <F = [tex]\frac{Adjacent}{Hypotenuse}[/tex]
= [tex]\frac{8}{17}[/tex]
iii. Tan <F = [tex]\frac{Opposite}{Adjacent}[/tex]
= [tex]\frac{15}{8}[/tex]
