The tangent to the curve at a point P (x, y) has slope dy/dx at that point. By the chain rule,
dy/dx = (dy/dθ) / (dx/dθ)
We're in polar coordinates, so
y (θ) = r (θ) sin(θ) ==> dy/dθ = dr/dθ sin(θ) + r (θ) cos(θ)
x (θ) = r (θ) cos(θ) ==> dx/dθ = dr/dθ cos(θ) - r (θ) sin(θ)
We're given r (θ) = 1 - sin(θ), so that
dr/dθ = -cos(θ)
Then the slope of the tangent to the curve at P is
dy/dx = (dr/dθ sin(θ) + r (θ) cos(θ)) / (dr/dθ cos(θ) - r (θ) sin(θ))
dy/dx = (-cos(θ) sin(θ) + (1 - sin(θ)) cos(θ)) / (-cos²(θ) - (1 - sin(θ)) sin(θ))
dy/dx = - (cos(θ) - sin(2θ)) / (sin(θ) + cos(2θ))
The tangent is horizontal if dy/dx = 0 (or when the numerator vanishes):
cos(θ) - sin(2θ) = 0
cos(θ) - 2 sin(θ) cos(θ) = 0
cos(θ) (1 - 2 sin(θ)) = 0
cos(θ) = 0 or 1 - 2 sin(θ) = 0
cos(θ) = 0 or sin(θ) = 1/2
[θ = π/2 + 2nπ or θ = 3π/2 + 2nπ] or [θ = π/6 + 2nπ or θ = 5π/6 + 2nπ]
where n is any integer.
In the interval 0 ≤ θ ≤ 2π, we get solutions of θ = π/6, θ = 5π/6, and θ = 3π/2. (We omit π/2 because the denominator is zero at that point and makes dy/dx undefined.) So the points where the tangent is horizontal are themselves (√3/4, 1/4), (-√3/4, 1/4), and (0, -2), respectively.
The tangent is vertical if 1/(dy/dx) = 0 (or when the denominator vanishes):
sin(θ) + cos(2θ) = 0
sin(θ) + (1 - 2 sin²(θ)) = 0
2 sin²(θ) - sin(θ) - 1 = 0
(2 sin(θ) + 1) (sin(θ) - 1) = 0
2 sin(θ) + 1 = 0 or sin(θ) - 1 = 0
sin(θ) = -1/2 or sin(θ) = 1
[θ = 7π/6 + 2nπ or θ = 11π/6 + 2nπ] or [θ = π/2 + 2nπ]
Then for 0 ≤ θ ≤ 2π, the tangent will be vertical for θ = 7π/6 and θ = 11π/6, which correspond respectively to the points (-3√3/4, -3/4) and (3√3/4, -3/4). (Again, we omit π/2 because this makes dy/dx non-existent.)
Please help !!!! will mark brainliest !!
Answer:
the first one
Step-by-step explanation:
Jack brought a new set of golf clubs of $186.75. The original price was $249. What percent of the original price did he pay?
133.3%
33.3%
25%
75%
Answer: 75%
Step-by-step explanation:
186.75/249 =.75
.75x100
75%
Type the correct answer in each box. Use numerals instead of words. If necessary, use / for the fraction bar(s).
Answer:
Slope: 2/3
Y-intercept: 6
Combine these radicals. 8 square root 5 + 2 square root 45
Answer
14√5
Step-by-step explanation:
8√5 + 2√45
= 8√5 + 6√5
= 14√5
Hope this helps
Answer:
[tex]\boxed {\boxed {\sf 14 \sqrt{5}}}[/tex]
Step-by-step explanation:
We are asked to combine the radicals. We have the following expression:
[tex]8 \sqrt{5} + 2 \sqrt{45}[/tex]
Currently, we cannot combine these radicals. The value under the square root is not the same for both terms.
However, we can simplify the radical 2 √45 because the value under the radical is divisible by a perfect square.
45 can be divided by 9 (the perfect square) for a quotient of 5. So, we can simplify the radical using this information.
Break the radical into 2 radicals: 9 and 5.
[tex]8 \sqrt{5}+ 2 \sqrt{9}\sqrt{5}[/tex]
Notice that a perfect square is under the radical. √9 can be simplifed to 3.
[tex]8 \sqrt{5}+ 2 *3 \sqrt{5}[/tex]
Multiply 2 and 3.
[tex]8 \sqrt{3} + 6 \sqrt{5}[/tex]
Now the value under the radical is the same for both terms, and we can add the numbers in front of the radicals.
[tex]14 \sqrt{5}[/tex]
The radicals combined is equal to 14√5
The population standard deviation for the temperature of beers found in Scooter's Tavern is 0.26 degrees. If we want to be 90% confident that the sample mean beer temperature is within 0.1 degrees of the true mean temperature, how many beers must we sample
Answer:
19 beers must be sampled.
Step-by-step explanation:
We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:
[tex]\alpha = \frac{1 - 0.9}{2} = 0.05[/tex]
Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].
That is z with a pvalue of [tex]1 - 0.05 = 0.95[/tex], so Z = 1.645.
Now, find the margin of error M as such
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.
The population standard deviation for the temperature of beers found in Scooter's Tavern is 0.26 degrees.
This means that [tex]\sigma = 0.26[/tex]
If we want to be 90% confident that the sample mean beer temperature is within 0.1 degrees of the true mean temperature, how many beers must we sample?
This is n for which M = 0.1. So
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
[tex]0.1 = 1.645\frac{0.26}{\sqrt{n}}[/tex]
[tex]0.1\sqrt{n} = 1.645*0.26[/tex]
[tex]\sqrt{n} = \frac{1.645*0.26}{0.1}[/tex]
[tex](\sqrt{n})^2 = (\frac{1.645*0.26}{0.1})^2[/tex]
[tex]n = 18.3[/tex]
Rounding up:
19 beers must be sampled.
PLEASE HELP!!! What is the equation of the line perpendicular to 2x – 3y = 13 that passes through the point (–6, 5)?
Answer:
2x + 3y -3=0
Step-by-step explanation:
The given equation of the line is ,
[tex]\implies 2x - 3y = 13 [/tex]
Now convert it into slope intercept form to get the slope , we get ,
[tex]\implies 3y = 2x - 13 \\\\\implies y =\dfrac{2}{3}x -\dfrac{13}{2}[/tex]
Therefore the slope is ,
[tex]\implies m = \dfrac{2}{3} [/tex]
We know that the product of slope of perpendicular lines is -1 . Therefore the slope of the perpendicular line will be ,
[tex]\implies m_{perpendicular}= -\dfrac{2}{3} [/tex]
Now one of the point is (-6,5) .On Using point slope form , we have ,
[tex]\implies y-y_1 = m( x - x_1) \\\\\implies y - 5 = -\dfrac{2}{3}( x + 6 ) \\\\\implies 3y - 15 = -2x -12
\\\\\implies 2x + 3y -15+12=0 \\\\\implies \underline{\underline{ 2x + 3y -3=0 }}[/tex]
Answer:
y = - [tex]\frac{3}{2}[/tex]x - 4
Step-by-step explanation:
2x – 3y = 13
3y = 2x + 13
y = [tex]\frac{2}{3}[/tex]x + [tex]\frac{13}{3}[/tex]
slope = 2/3
negative reciprocal = -3/2
y = -3/2x + b
(-6, 5)
5 = (-3/2)(-6) + b
5 = 9 + b
b = -4
y = -3/2x - 4
3. Of 1000 randomly selected cases of lung cancer, 450 resulted in death within 5 years. Calculate a 96% CI on the death rate from lung cancer.
Answer:
The 96% CI on the death rate from lung cancer is (0.4177, 0.4823).
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
Of 1000 randomly selected cases of lung cancer, 450 resulted in death within 5 years.
This means that [tex]n = 1000, \pi = \frac{450}{1000} = 0.45[/tex]
96% confidence level
So [tex]\alpha = 0.04[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.04}{2} = 0.98[/tex], so [tex]Z = 2.054[/tex].
The lower limit of this interval is:
[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.45 - 2.054\sqrt{\frac{0.45*0.55}{1000}} = 0.4177[/tex]
The upper limit of this interval is:
[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.45 + 2.054\sqrt{\frac{0.45*0.55}{1000}} = 0.4823[/tex]
The 96% CI on the death rate from lung cancer is (0.4177, 0.4823).
7 is added to the product of 5 and 6
Answer:
37
Step-by-step explanation:
7 + (5×6)
= 7 + 30
= 37
.................
Answer:
37
Step-by-step explanation:
First Step: Multiply
5x6=30
Second Step: Add
30+7=37
Therefore your answer is 37
Hope this helps and if it does, don't be afraid to give my answer a "Thanks" and maybe a Brainliest if it's correct?
Study the table representing the price of different amounts of apples, in pounds, and then complete the sentences. The constant difference in the y-values is . The linear function is .
Answer: the first part is 1.25. The second part is y=1.25x
Step-by-step explanation: edge 2021
Helppp and explain!!!
* Insert a digit to make numbers that are divisible by 6 if it is possible:
234_6
Answer:
i put in 3 to make 23436 because 36 is divisible by 6
Suppose that 20° of boys opted for mathematics and 40% of girls opted for mathematics. What is the probability that a student opted for mathematics if half of the class is girls?
Answer: 30%
Step-by-step explanation:
Let A be the probability of a student opting for mathematics - it consists of either boy opting for mathematics or girl opting for mathematics. As there is "or" we need to sum these probabilities.
[tex]P(A) = P(B)* P(M|G) + P(G)*P(M|G)[/tex]
[tex]P(A) = \frac{1}{2} * \frac{20}{100} + \frac{1}{2} * \frac{40}{100}[/tex]
[tex]P(A) = 3/10 = 0.3[/tex]
=> 30%
Answer:
30% Chance
Step-by-step explanation:
This one is rather simple. If half the class is girls, split 40 into half. Do the same with 20 if half is boys. Add 10 and 20 and you get 30.
if 2 (3x - 4 ) =5, then x =
Answer:
2.167 (rounded to the nearest hundredths).
Step-by-step explanation:
Isolate the variable, x. Note the equal sign, what you do to one side, you do to the other. Do the opposite of PEMDAS.
PEMDAS is the order of operations, and stands for:
Parenthesis
Exponents (& Roots)
Multiplication
Division
Addition
Subtraction
~
First, divide 2 from both sides of the equation:
(2(3x - 4))/2 = (5)/2
3x - 4 = 2.5
Next, isolate the variable, x. Add 4 to both sides of the equation:
3x - 4 (+4) = 2.5 (+4)
3x = 2.5 + 4
3x = 6.5
Then, divide 3 from both sides of the equation:
(3x)/3 = (6.5)/3
x = 6.5/3 = 2.167 (rounded).
~
Answer:
We have this equation
2*(3x-4) = 5
We can start solving the parentheses
2*(3x- 4) = 5
6x - 8 = 5
We can add 8 to both sides
6x - 8 + 8 = 5 + 8
6x = 13
And divide by 6
6x/6 = 13/6
x = 13/6
which of the following is the median of 19, 31, 15, 50, 20
[tex]\huge\textsf{Hey there!}[/tex]
[tex]\large\text{19, 31, 15, 50, \& 20}[/tex]
[tex]\large\text{When you see or hear the word \underline{median}, think of the question}\\\large\text{asking you \bf what is the MIDDLE NUMBER.}\large\text{To find the}\\\large\text{middle number you have to put the numbers from descending}\\\large\text{(least/decreasing) or ascending (greatest/increasing) order}[/tex]
[tex]\large\text{15, 19, 20, 31, \& 20}[/tex]
[tex]\large\text{Make sure it is even on BOTH SIDES of the DATA SET}[/tex]
[tex]\large\text{It seems to be even on both sides of the number \bf 20}\large\text{ so \underline{20}}\\\large\text{can be your median/middle number in this given set}[/tex]
[tex]\boxed{\boxed{\huge\textsf{Answer: the median is \bf 20}}}\huge\checkmark[/tex]
[tex]\large\text{Good luck on your assignment and enjoy your day!}\\\\\\\\\\\frak{Amphitrite1040:)}[/tex]
Please help
Find the value of x,
m∠5 = x-6, m∠4 = 2x+4, m∠2 = 2x-26
9514 1404 393
Answer:
x = 30 2/3
Step-by-step explanation:
Angles 4 and 5 are complementary, so we have ...
m∠4 +m∠5 = 90°
(2x +4) +(x -6) = 90
3x -2 = 90 . . . . . . . . . collect terms
3x = 92 . . . . . . . . . . add 2; next, divide by 3
x = 92/3 = 30 2/3
A fair dice is rolled. Work out the probability of getting a number less than 5. Give your answer in its simplest form.
Step-by-step explanation:
4/6
=2/3
That's what I could show you
Write the range of the function using interval notation.
Answer:
[-3, -1]
Step-by-step explanation:
The minimum y value is -3.
The maximum y value is -1.
-3 and -1 are included, so we use square brackets.
Answer: [-3, -1]
Please help!!! Picture included
Step-by-step explanation:
A is your answer.
You just have to solve for each function individually and see what the roots are.
9514 1404 393Answer:
(a) f(x) = 2x² -2
Step-by-step explanation:
The function has two zeros, at -1 and 1, so is not a linear or square root function. The only viable choice is the correct one:
f(x) = 2x² -2
insert a digit in a place of each "..." to make numbers that are divisible by 6 if it is possible: 4...6
Answer:
1 There is no number that make it divisible by 6 with no decimals
2 1,4,7
Step-by-step explanation:
2 23718/6= 3953
23748/6= 3958
23778/6= 3963
I really don’t understand graphs
simplify 3x⁵y³ ÷2y² step by step
Answer:
3/2 x^5 y
Step-by-step explanation:
3x^5y^3
----------------
2y^2
Simplify the y terms
y^3 / y^2 = y^(3-2) = y
3/2 x^5 y
Answer:
[tex] \frac{3}{2} x {}^{5} y {}^{} [/tex]
Step-by-step explanation:
it's all in the image
what is the value of x
chang knows one side of a triangle is 13 cm which set of two sides is possible for the length of the other two sides
5 cm and 8 cm
6cm and 7 cm
7cm and 2 cm
8cm and 9 cm
Answer:
i dont knowwww dhehje ejhdjeke jsienje
Answer:
8cm and 9 cm
Step-by-step explanation:
Sum of sides rule:
The sum of the two smallest sides of a triangle has to be greater than the third side.
5 cm and 8 cm
One side is 5, other 8, 5 + 8 = 13. The sum has to be greater than 13, so this is not possible.
6cm and 7 cm
6 + 7 = 13, same as above, not possible.
7cm and 2 cm
7 + 2 = 9 < 13, so not possible.
8cm and 9 cm
8 + 9 = 17 > 13, so possible, and this is the answer.
SCALCET8 3.9.003. Each side of a square is increasing at a rate of 4 cm/s. At what rate is the area of the square increasing when the area of the square is 9 cm2
Answer: [tex]24\ cm^2/s[/tex]
Step-by-step explanation:
Given
Each side of square is increasing at a rate of 4 cm/s
Side of a square when area is [tex]9\ cm^2[/tex]
Suppose a is side of the square
[tex]\Rightarrow a=\sqrt{9}\\\Rightarrow a=3\ cm[/tex]
Area is given by
[tex]\Rightarrow A=a^2\\\text{Differentiate area w.r.t time}\\\\\Rightarrow \dfrac{dA}{dt}=2a\dfrac{da}{dt}\\\\\Rightarrow \dfrac{dA}{dt}=2\times 3\times 4\\\\\Rightarrow \dfrac{dA}{dt}=24\ cm^2/s[/tex]
Area is increasing at a rate of [tex]24\ cm^2/s[/tex]
Answer:
24cm^2/ s
Step-by-step explanation:
Johnny tripled his baseball card collection. Then he added 6 more cards to the collection. Now he has 24 cards. How many cards did he start with?
9514 1404 393
Answer:
6
Step-by-step explanation:
Work backward.
If he has 24 after adding 6, he had 18 before that addition.
If he had 18 after tripling his collection, he had 18/3 = 6 cards to start with.
__
Note that this is the same process you would use if you started with an equation.
3c +6 = 24 . . . . where c is the number of cards Johnny started with
3c = 24 -6 = 18 . . . . . subtract 6 from the final number
c = 18/3 = 6 . . . . . . . . divide the tripled value by 3 to see the original value
Johnny started with 6 cards.
Test the claim that the mean GPA of night students is larger than the mean GPA of day students at the 0.10 significance level. The null and alternative hypothesis would be: H 0 : p N ≥ p D H 1 : p N < p D H 0 : p N ≤ p D H 1 : p N > p D H 0 : p N = p D H 1 : p N ≠ p D H 0 : μ N ≤ μ D H 1 : μ N > μ D H 0 : μ N ≥ μ D H 1 : μ N < μ D H 0 : μ N = μ D H 1 : μ N ≠ μ D The test is: two-tailed right-tailed left-tailed The sample consisted of 30 night students, with a sample mean GPA of 3.34 and a standard deviation of 0.02, and 30 day students, with a sample mean GPA of 3.32 and a standard deviation of 0.08. The test statistic is: (to 2 decimals) Use the conservative degree of freedoms. The p-value is: (to 2 decimals) Based on this we: Reject the null hypothesis Fail to reject the null hypothesis
Answer:
H0 : μN ≤ μD
H1 : μN > μD
Right tailed
Test statistic = 1.33
Pvalue = 0.097
Fail to reject the Null
Step-by-step explanation:
H0 : μN ≤ μD
H1 : μN > μD
The test is right tailed ; culled from the direction of the greater than sign ">"
Night students :
n1 =30 x1= 3.34 s1 = 0.02
Day students:
n2 = 30 x2 = 3.32 s2 = 0.08
The test statistic :
(x1 - x2) / √(s1²/n1) + (s2²/n2)
T= (3.34 - 3.32) / √(0.02²/30) + (0.08²/30)
T = 0.02 / 0.0150554
Test statistic = 1.328
Using the conservative approach ;
df = Smaller of n1 - 1 or n2 - 1
df = 30 - 1 = 29
Pvalue(1.328, 29) = 0.097
At α = 0.10
Pvalue < α ; Hence, we reject H0 ; and conclude that there is significant evidence that GPA of night student is greater than GPA of day student
x(x-y) - y( x- y) simplify
Step-by-step explanation:
x²-xy-xy+y²
x²+2xy+y²
hope it helps
The half-life of a newly discovered radioactive element is 30 seconds. To the nearest tenth of a second, how long will it take for a sample of 9 grams to decay to 0.72 grams
Answer:
It will take about 109.3 seconds for nine grams of the element to decay to 0.72 grams.
Step-by-step explanation:
We can write a half-life function to model our function.
A half-life function has the form:
[tex]\displaystyle A=A_0\left(\frac{1}{2}\right)^{t/d}[/tex]
Where A₀ is the initial amount, t is the time that has passes (in this case seconds), d is the half-life, and A is the amount after t seconds.
Since the half-life of the element is 30 seconds, d = 30. Our initial sample has nine grams, so A₀ is 9. Substitute:
[tex]\displaystyle A=9\left(\frac{1}{2}\right)^{t/30}[/tex]
We want to find the time it will take for the element to decay to 0.72 grams. So, we can let A = 0.72 and solve for t:
[tex]\displaystyle 0.72=9\left(\frac{1}{2}\right)^{t/30}[/tex]
Divide both sides by 9:
[tex]\displaystyle 0.08=\left(\frac{1}{2}\right)^{t/30}[/tex]
We can take the natural log of both sides:
[tex]\displaystyle \ln(0.08)=\ln\left(\left(\frac{1}{2}\right)^{t/30}\right)[/tex]
By logarithm properties:
[tex]\displaystyle \ln(0.08)=\frac{t}{30}\ln(0.5)[/tex]
Solve for t:
[tex]\displaystyle t=\frac{30\ln(0.08)}{\ln(0.5)}\approx109.3\text{ seconds}[/tex]
So, it will take about 109.3 seconds for nine grams of the element to decay to 0.72 grams.
Which of the following choices is the average speed of a tourist who traveled for 1 hour on a plane at 400 mph and 4 hours by car at 60 mph?
(average= total miles/total hours)
Answer:
128 mph
Step-by-step explanation:
1 hour = 400
4 hours = 240
240+400= 640
4+1 = 5
640/5=128
Hello can anyone pls help with this multiple choice question
Answer:
The correct answer is the last one
Step-by-step explanation:
