Answer:
1/10
Step-by-step explanation:
There are 5 numbers in the range that are multiples of 10: 10, 20, 30, 40, 50. The probability of choosing one of those at random from the set of 50 numbers is ...
5/50 = 1/10
Do phone surveys provide adequate coverage of households with respect to one particular parameter? The parameter is the proportion of households without children. If telephone surveys provide adequate coverage of households, then p , the proportion of households without children in the set of all future samples reached by phone, must be equal to the proportion of households without children in the population of all households. Suppose that Thomas, a market analyst, contacts a simple random sample of 300 households as part of a national telephone survey. Of the households contacted, 129 households, or 43 %, have no children and 57 % have at least one child. The most recent census indicates that 48 % of all households have no children and 52 % have at least one child.
Complete Question
The complete question is shown on the first uploaded image
Answer:
Based on the result of his test , Thomas should fail to reject null hypothesis at a significance level of 0.01. Thomas sufficient evidence to conclude that the proportion of households without children in the set of all future samples reached by phone is not equal to the proportion of households without children in the population of all households.
Step-by-step explanation:
From the question we see that the p-value is greater than the level of significance (0.01 )so we fail to reject the null hypothesis.
This means that Thomas has sufficient evidence to conclude that the proportion of households without children in the set of all future samples reached by phone is not equal to the proportion of households without children in the population of all households.
Given m -1/2 & the point ( 3, -6), which is the point slope form of the equation?
Answer:
[tex]y+6=-\frac{1}{2} (x-3)[/tex]
Step-by-step explanation:
Since point-slope form is [tex]y-y1=m(x-x1)[/tex], you have to plug in the values given to you to create the equation. The "y1" is the "y" coordinate given to us, while the x1 is the x coordinate given to us. So, you have to plug in the x and y coordinates, 3 and -6, into the equation. Since two negatives cancel out to be a positive, y--6= y+6. The "m" stands for the slope, so -1/2 is inserted into the equation, giving us [tex]y+6=-\frac{1}{2} (x-3)[/tex].
Find the Correlation of the following two variables X: 2, 3, 5, 6 Y: 1, 2, 4, 5
Answer:
The correlation of X and Y is 1.006
Step-by-step explanation:
Given
X: 2, 3, 5, 6
Y: 1, 2, 4, 5
n = 4
Required
Determine the correlation of x and y
Start by calculating the mean of x and y
For x
[tex]M_x = \frac{\sum x}{n}[/tex]
[tex]M_x = \frac{2 + 3+5+6}{4}[/tex]
[tex]M_x = \frac{16}{4}[/tex]
[tex]M_x = 4[/tex]
For y
[tex]M_y = \frac{\sum y}{n}[/tex]
[tex]M_y = \frac{1+2+4+5}{4}[/tex]
[tex]M_y = \frac{12}{4}[/tex]
[tex]M_y = 3[/tex]
Next, we determine the standard deviation of both
[tex]S = \sqrt{\frac{\sum (x - Mean)^2}{n - 1}}[/tex]
For x
[tex]S_x = \sqrt{\frac{\sum (x_i - Mx)^2}{n -1}}[/tex]
[tex]S_x = \sqrt{\frac{(2-4)^2 + (3-4)^2 + (5-4)^2 + (6-4)^2}{4 - 1}}[/tex]
[tex]S_x = \sqrt{\frac{-2^2 + (-1^2) + 1^2 + 2^2}{3}}[/tex]
[tex]S_x = \sqrt{\frac{4 + 1 + 1 + 4}{3}}[/tex]
[tex]S_x = \sqrt{\frac{10}{3}}[/tex]
[tex]S_x = \sqrt{3.33}[/tex]
[tex]S_x = 1.82[/tex]
For y
[tex]S_y = \sqrt{\frac{\sum (y_i - My)^2}{n - 1}}[/tex]
[tex]S_y = \sqrt{\frac{(1-3)^2 + (2-3)^2 + (4-3)^2 + (5-3)^2}{4 - 1}}[/tex]
[tex]S_y = \sqrt{\frac{-2^2 + (-1^2) + 1^2 + 2^2}{3}}[/tex]
[tex]S_y = \sqrt{\frac{4 + 1 + 1 + 4}{3}}[/tex]
[tex]S_y = \sqrt{\frac{10}{3}}[/tex]
[tex]S_y = \sqrt{3.33}[/tex]
[tex]S_y = 1.82[/tex]
Find the N pairs as [tex](x-M_x)*(y-M_y)[/tex]
[tex](2 - 4)(1 - 3) = (-2)(-2) = 4[/tex]
[tex](3 - 4)(2 - 3) = (-1)(-1) = 1[/tex]
[tex](5 - 4)(4 - 3) = (1)(1) = 1[/tex]
[tex](6-4)(5-3) = (2)(2) = 4[/tex]
Add up these results;
[tex]N = 4 + 1 + 1 + 4[/tex]
[tex]N = 10[/tex]
Next; Evaluate the following
[tex]\frac{N}{S_x * S_y} * \frac{1}{n-1}[/tex]
[tex]\frac{10}{1.82* 1.82} * \frac{1}{4-1}[/tex]
[tex]\frac{10}{3.3124} * \frac{1}{3}[/tex]
[tex]\frac{10}{9.9372}[/tex]
[tex]1.006[/tex]
Hence, The correlation of X and Y is 1.006
how would you write six times the square of a number
Answer:
[tex]\huge \boxed{6x^2 }[/tex]
Step-by-step explanation:
6 times a number squared.
Let the number be [tex]x[/tex].
6 is multiplied to [tex]x[/tex] squared.
[tex]6 \times x^2[/tex]
the difference of two complementary angles is 17 degrees. find the measures of the angles
Answer:
The angle measures are 53.5° and 36.5°.
Step-by-step explanation:
We can create a systems of equations, assuming x and y are the angle measures.
Since the two angles are complementary, their angle measures will add up to 90.
x + y = 90
x - y = 17
We can now use the process of elimination, and end up with:
2x = 107
Dividing both sides by two gets us
x = 53.5
Substituting this value into an equation will get us y
53.5 + y = 90
y = 36.5
Hope this helped!
The Centers for Disease Control and Prevention (CDC) report that gastroenteritis, or stomach flu, is the most frequently reported type of recreational water illness. Gastroenteritis is a viral or bacterial infection that spreads through contaminated food and water. Suppose that inspectors wish to determine if the proportion of public swimming pools nationwide that fail to meet disinfectant standards is different from 10.7%, which was the proportion of pools that failed the last time a comprehensive study was done, 2008.
A simple random sample of 30 public swimming pools was obtained nationwide. Tests conducted on these pools revealed that 26 of the 30 pools had the required pool disinfectant levels.
Does this sample meet the requirements for conducting a one-sample z ‑test for a proportion?
a. No, the requirements are not met because the population standard deviation is not known.
b. No, the requirements are not met because the sample has fewer than 10 failures, which violates the condition for approximating a normal distribution.
c. No, the requirements are not met because the sample is not random, even though the number of successes and the number of failures are both at least 10, ensuring that the distribution is approximately normal.
d. Yes, the requirements are met because the sample size is more than 30, ensuring that the distribution is approximately normal.
e. Yes, the requirements are met because the number of successes and the number of failures of this random sample are both at least 10, ensuring that the distribution is approximately normal.
b. No, the requirements are not met because the sample has fewer than 10 failures, which violates the condition for approximating a normal distribution.
Step-by-step explanation:
from the question, the number of successes is equal to 30
and it is more than the number of failures
for us to conduct this test such as the z test the data we are using should be a random sample from the population that we are interested in. the population should be at least as big as the sample by 10 times. first of all We need to check if the mean of the sample is normally distributed.
if 26 are successes out of a sample of 30, then failures would be 4. therefore option b is correct.
Find the vector and parametric equations for the line through the point P(0, 0, 5) and orthogonal to the plane −1x+3y−3z=1. Vector Form: r
Answer:
Note that orthogonal to the plane means perpendicular to the plane.
Step-by-step explanation:
-1x+3y-3z=1 can also be written as -1x+3y-3z=0
The direction vector of the plane -1x+3y-3z-1=0 is (-1,3,-3).
Let us find a point on this line for which the vector from this point to (0,0,5) is perpendicular to the given line. The point is x-0,y-0 and z-0 respectively
Therefore, the vector equation is given as:
-1(x-0) + 3(y-0) + -3(z-5) = 0
-x + 3y + (-3z+15) = 0
-x + 3y -3z + 15 = 0
Multiply through by - to get a positive x coordinate to give
x - 3y + 3z - 15 = 0
Match the ones on the left to the right
Answer/Step-by-step explanation:
[tex] (4 + 5) + 2 = 4 + (5 + 2) [/tex] => any combination of numbers were formed or grouped when adding. The associative property of addition was applied.
[tex] 2(2x + 4) = 4x + 8 [/tex] => the sum of two terms (addend) are multiplied by by a number separately (I.e., a(b + c) = a(b) + a(c) = ab + ac). The property applied is distributive property.
[tex] (7x * x) * 3 = 7 * (x * 3) [/tex] => the numbers were grouped in any combination to arrive at same result when multiplying. Associative property of multiplication was applied.
[tex] (8 * x * 2) = (x * 8 * 2) [/tex] => the numbers where ordered in any manner to arrive at same result when multiplying. Cummutative property of multiplication was applied.
[tex] (7 + 3) + 1 = (1 + (7 + 3) [/tex] => the order in which the nnumbers in the were arranged doesn't matter, as same result is arrive at. This is Cummutative property of addition.
Ashton needs to rent a car while on vacation. The rental company charges $19.95, plus 18 cents for each mile driven. If Ashton only has $50 to spend on the car rental, what is the maximum number of miles she can drive?
Answer:
166.9 miles or 166 miles
Step-by-step explanation:
We can form an equation like this:
19.95 + .18x = 50
In this equation, "x" is the number of miles.
=> 19.95 - 19.95 +.18x = 50 -19.95
=> .18x = 30.05
=> .18x/.18 = 30.05/.18
=> x = 166.9
Ashton can drive 166.9 miles.
**Note: We cannot round the answer to 167, as she would not have enough money to drive the extra 0.1 mile.
Money is invested into an account earning 4.25% interest compounded annually. If the accumulated value after 18 years
will be $25,000, approximately how much money is presently in the account?
a $5,875
b. $11,820
c. $19,125
d. $23,960
Answer:
b. $11,820
Step-by-step explanation:
The 'rule of 72' tells you the doubling time of this account is about ...
(72 years)/(4.25) = 16.9 years
So, in 18 years, the amount will be slightly more than double the present value. That is, the present value is slightly less than half the future amount.
$25,000/2 = $12,500
The closest answer choice is ...
$11,820
__
The present value of that future amount is ...
PV = FV×(1 +r)^-t = $25,000×1.0425^-18 ≈ $11,818.73
The present value is about $11,820.
Answer:
B
Step-by-step explanation:
find the dimension of the swimming pool if the sum must be 50 feet and the length must be 3 times the depth.
Answer:
depth 5 8.3 ft, length 5 24.9 ft, width 5 16.8 ft
[tex](y - 1) log_{10}(4?) = log_{10}(16?) [/tex]
find the value of y
Answer:
3Step-by-step explanation:
Given the log function [tex](y-1)log_{10}(4) = log_{10} 16\\ \\[/tex] to get the value of y, the following steps must be carried out;
[tex](y-1)log_{10}(4) = log_{10} 16\\\\(y-1)log_{10}(2^2) = log_{10} 2^4\\\\ (y-1)2log_{10}(2) = 4log_{10} 2\\ \\DIvide\ both\ sides\ by \ log_{10}2\\\\\frac{2(y-1)log_{10}2 }{log_{10}2} = \frac{4log_{10}2}{log_{10}2} \\\\2(y-1) = 4\\\\[/tex]
Open the bracket
[tex]2y-2(1) = 4\\\\2y -2 = 4\\\\add \ 2 \ to \ both \ sides\\\\2y-2+2 = 4+2\\\\2y = 6\\\\Divide \ both \ sides\ by \ 2\\\\2y/2 = 6/2\\\\y = 3[/tex]
Hence the value of y is 3
A baking scale measures mass to the tenth of a gram, up to 650 grams. Which of the following measurements is possible using this scale? a.3.8 grams b.120.01 grams c.800.0 grams d.54 milligrams
Answer:
Step-by-step explanation:
The answer is b
120.01 grams
7 less than the quotient of a number and 3 is 5. Find the number.
Answer:
The answer is 36
Step-by-step explanation:
Let the number be x
7 less than the quotient of a number and 3 is written as
[tex] \frac{x}{3} - 7[/tex]The result is 5
So we have
[tex] \frac{x}{3} - 7 = 5[/tex]Move - 7 to the right side of the equation
That's
[tex] \frac{x}{3} = 7 + 5[/tex][tex] \frac{x}{3} = 12[/tex]Multiply both sides by 3 to make x stand alone
We have
[tex]3 \times \frac{x}{3} = 12 \times 3[/tex]We have the final answer as
x = 36Hope this helps you
According to the South Dakota Department of Health, the number of hours of TV viewing per week is higher among adult women than adult men. A recent study showed women spent an average of 34 hours per week watching TV, and men, 29 hours per week. Assume that the distribution of hours watched follows the normal distribution for both groups, and that the standard deviation among the women is 4.5 hours and is 5.1 hours for the men.a. What percent of the women watch TV less than 40 hours per week? (Round z-score computation to 2 decimal places and your final answer to 4 decimal places.)b. What percent of the men watch TV more than 25 hours per week? (Round z-score computation to 2 decimal places and your final answer to 4 decimal places.)c. How many hours of TV do the one percent of women who watch the most TV per week watch? Find the comparable value for the men. (Round your answers to 3 decimal places.)
Answer:
a) P(x<40) = 0.90824
Therefore, the percent of the women watch TV less than 40 hours per week is 0.90824 × 100 = 90.8240%
b)P(x>25) = 1 - P(z = -0.78) = 0.7823
Therefore, percent of the men watch TV more than 25 hours per week?is 0.7823 × 100 = 78.230%
c)The number of hours that the one percent of WOMEN who watch the most TV per week watch is for 44.485hours
While, for the MEN, the number of hours that the one percent of men who watch the most TV per week watch is for 40.883 hours
Step-by-step explanation:
To solve this question, we would be using z score formula:
z = (x-μ)/σ,
where x is the raw score
μ is the population mean
σ is the population standard deviation.
a. What percent of the women watch TV less than 40 hours per week? (Round z-score computation to 2 decimal places and your final answer to 4 decimal places.)
z = (x-μ)/σ,
where x is the raw score = 40 hours
μ is the population mean = 34 hours
σ is the population standard deviation = 4.5
z = (40 - 34)/4.5
z = 1.33333
Approximately to 2 decimal places = z score = 1.33
Using the normal distribution z score table
Probabilty value from Z-Table:
P(z = 1.33) = P(x<40) = 0.90824
Therefore, the percent of the women watch TV less than 40 hours per week is 0.90824 × 100 = 90.8240%
b. What percent of the men watch TV more than 25 hours per week? (Round z-score computation to 2 decimal places and your final answer to 4 decimal places.)
z = (x-μ)/σ,
where x is the raw score = 25 hours
μ is the population mean = 29 hours
σ is the population standard deviation = 5.1
z = (25 - 29)/5.1
z = -0.78431
Approximately to 2 decimal places
z score = -0.78
Using the z score normal distribution table:
Probability value from Z-Table:
P(z = -0.78) = P(x<Z) = 0.2177
P(x>25) = 1 - P(z = -0.78) = 0.7823
Therefore, percent of the men watch TV more than 25 hours per week?is 0.7823 × 100 = 78.230%
c. How many hours of TV do the one percent of women who watch the most TV per week watch? Find the comparable value for the men. (Round your answers to 3 decimal places.)
First, we find what the z score is.
We were asked in the question to find how many hours 1% of the women watch TV the most.
We have to find the confidence interval
100 - 1% = 99%
The z score for the confidence interval of 99% or 0.99(in decimal form) = 2.33
z score = 2.33
Since we know the z score now, we proceed to find x = raw score.
z = (x-μ)/σ,
where x is the raw score = unknown
μ is the population mean = 34 hours
σ is the population standard deviation = 4.5
2.33= (x - 34)/4.5
Cross Multiply
2.33 × 4.5 = x - 34
10.485 = x - 34
x = 10.485 + 34
x = 44.485 hours.
Therefore, the number of hours that the one percent of women who watch the most TV per week watch is for 44.485hours
In the question, we were also asked to find the comparable value for men.
Hence, for one percent of the men.
We determine what the z score is.
We were asked in the question to find how many hours 1% of the men watch TV the most.
We have to find the confidence interval
100 - 1% = 99%
The z score for the confidence interval of 99% or 0.99(in decimal form) = 2.33
We already have our z score as 2.33
z = (x-μ)/σ,
where x is the raw score = unknown
μ is the population mean = 29 hours
σ is the population standard deviation = 5.1
2.33= (x - 29)/5.1
Cross Multiply
2.33 × 5.1 = x - 29
11.883 = x - 29
x = 11.883 + 29
x = 40.883 hours.
Therefore, the number of hours that the one percent of men who watch the most TV per week watch is for 40.883 hours
Find x. A. 44√3 B. 33 C. 33√2 D. 11√3
Answer:
B
Step-by-step explanation:
Sin 45 = y/(11√6)
1/√2 = y/(11√6)
y= (11√6)/√2
y= 11√3
tan 60 = x/y
√3 = x/y
x = y√3
= (11√3)√3
= 11(3)
= 33
what is the distance between the points (4 3) and (1 -1) on the cordinate plane
Answer:
d = 5
Step-by-step explanation:
Distance formula: [tex]d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]
d = sqrt[(1-4)^2+(-1-3)^2]
d = 5
Answer:
5
Step-by-step explanation:
distance = square root of (1-4)^2 + (-1-3)^2
=> distance = square root of -3^2 + (-4)^2
=> distance = square root of 9 + 16
=> distance = square root of 25
=> distance = 5
Transform the given parametric equations into rectangular form. Then identify the conic. x= -3cos(t) y= 4sin(t)
Answer:
Solution : Option D
Step-by-step explanation:
The first thing we want to do here is isolate the cos(t) and sin(t) for both the equations --- ( 1 )
x = - 3cos(t) ⇒ x / - 3 = cos(t)
y = 4sin(t) ⇒ y / 4 = sin(t)
Let's square both equations now. Remember that cos²t + sin²t = 1. Therefore, we can now add both equations after squaring them --- ( 2 )
( x / - 3 )² = cos²(t)
+ ( y / 4 )² = sin²(t)
_____________
x² / 9 + y² / 16 = 1
Remember that addition indicates that the conic will be an ellipse. Therefore your solution is option d.
How many solutions does 2−9x=−6x+5−3x have?
Answer:
There are no values of x that make the equation true.
No solution
Step-by-step
hope it help
Hi
2-9x = -6x+5-3x
-9x+6x+3x = 5-2
0x = 3
as 0 ≠ 3 , there is no answer possible to your equation.
Recall the formula V = four-thirds pi r cubed.
Answer:
1308.33
Step-by-step explanation:
In the pic
You catch an expected number of 1.51.5 fish per hour. You can catch a fish at any instant of time. Which distribution best characterizes the number of fish you catch in one hour of fishing
Answer:
The distribution is Poisson distribution
Step-by-step explanation:
From the question we are told that
An expected number of fish was caught per hour is 1.5
The distribution that best characterize the number of fish you catch in one hour of fishing is the Poisson distribution
This because generally the Poisson distribution is a distribution that shows the number of times a given event will occur within a defined period of time
A circle has center (3, -5) and the point (-1, -8) lies on the circumference of the circle. What is the equation of the circle in Standard Form?
Answer:
[tex] {(x - 3)}^{2} + {(y + 5)}^{2} = {5}^{2} [/tex]
Step-by-step explanation:
First find the radius
Which is the distance between the 2 points.
Radius =5
The answer in the standad form is above.
The equation of the circle in Standard Form is (x - 3)² + (y + 5)² = 25
The standard equation of a circle is given as:
(x - a)² + (y - b)² = r²
where (a, b) is the center of the circle and r is the radius of the circle.
Given the center as (3, -5) hence the radius of the circle is the distance between (3, -5) and (-1, -8). Hence:
[tex]Radius=\sqrt{(-8-(-5))^2+(-1-3)^2} \\\\Radius=5\ units\\[/tex]
hence:
(x - 3)² + (y - (-5))² = 5²
(x - 3)² + (y + 5)² = 25
The equation of the circle in Standard Form is (x - 3)² + (y + 5)² = 25
Find out more at: https://brainly.com/question/13658927
Ava started her hw at 7:20pm she finished it at 8:05 pm how long did she take to her hw?
Answer:
45 mins
Step-by-step explanation:
illustrate the distributive property to solve 144/8
Answer:
8 (19) or 8 (18 +1)
Step-by-step explanation:
Distributive property means to distribute.
HCF of 144 and 8.
=> 8 is the HCF of 144 and 8
8 (18 + 1)
=> 8 (19)
Help please!!!!!!!!!!!!
==================================================
Explanation:
When we reflect any point (x,y) over the line y = x, the x and y coordinates swap. So for instance, we have K = (5, -9) turn into K ' = (-9, 5).
Consider a point like (1,2). We can move it down 1 unit to have it land on the line y = x, then we can move it one unit to the right to move it to (2,1). These two translations effectively move the original point to its reflected location. The distance from (1,2) to y = x, is the same as the distance from (2,1) to y = x. Furthermore, the line connecting (1,2) to (2,1) is perpendicular to y = x.
WILL MARK BRAINIEST!!! Segment AC has two endpoints; (-2,5) and (2,-5). What are the coordinates of point B on segment AC such that the ratio of AB to BC is 5:1? Any help would be appreciated; first correct answer get brainiest and a 5 star review!
Answer:
[tex](\frac{4}{3},-\frac{10}{3})[/tex]
Step-by-step explanation:
If the extreme ends of a line segment AC are A[tex](x_1,y_1)[/tex] and C[tex](x_2,y_2)[/tex].
If a point B(x, y) divides the segment in the ratio of m : n
Then the coordinates of the point B are,
x = [tex]\frac{mx_2+nx_1}{m+n}[/tex]
y = [tex]\frac{my_2+ny_1}{m+n}[/tex]
If the ends of AC are A(-2, 5) and C(2, -5) and a point B divides it in the ratio of m : n = 5 : 1
Therefore, coordinates of this point will be,
x = [tex]\frac{5\times (2)+1(-2)}{5+1}[/tex]
= [tex]\frac{10-2}{5+1}[/tex]
= [tex]\frac{8}{6}[/tex]
= [tex]\frac{4}{3}[/tex]
y = [tex]\frac{5\times (-5)+1(5)}{5+1}[/tex]
= [tex]\frac{-25+5}{6}[/tex]
= [tex]-\frac{20}{6}[/tex]
= [tex]-\frac{10}{3}[/tex]
Therefore, coordinates of the point B are [tex](\frac{4}{3},-\frac{10}{3})[/tex].
Describe in words how you would solve
the linear system y = 3x + 1 and y = - 2x + 3.
Answer:
Below.
Step-by-step explanation:
As both the right sides of the 2 equations are equal to y, by the transitive law of equality 3x + 1 = -2x + 3.
W then solve this equation for x then substitute this value of x in the first equation ( y = 3x + 1) to find the value of y.
Identify the vertex of the graph. Tell whether it is a minimum or maximum.
(-2,-2); maximum
(-2,-2); minimum
(-2, -1); minimum
(-2, -1); maximum
Answer:
(-2,-2); minimum
Step-by-step explanation:
From the graph, the vertex is (-2, -2) and since there are no y values that go less than the y value of the vertex, it is a minimum.
Please help with this
The shape has 11 sides.
Using the angle formula for polygons:
The sum of all the interior angles is:
11-2 x 180 = 9 x 180 = 1,620 degrees.
For one angle divide the total by number of sides:
1620 / 11 = 147.27 which rounds to 147.2
The answer is D.
Change each of the following points from rectangular coordinates to spherical coordinates and to cylindrical coordinates.
a. (4,2,−4)
b. (0,8,15)
c. (√2,1,1)
d. (−2√3,−2,3)
Answer and Step-by-step explanation: Spherical coordinate describes a location of a point in space: one distance (ρ) and two angles (Ф,θ).To transform cartesian coordinates into spherical coordinates:
[tex]\rho = \sqrt{x^{2}+y^{2}+z^{2}}[/tex]
[tex]\phi = cos^{-1}\frac{z}{\rho}[/tex]
For angle θ:
If x > 0 and y > 0: [tex]\theta = tan^{-1}\frac{y}{x}[/tex];If x < 0: [tex]\theta = \pi + tan^{-1}\frac{y}{x}[/tex];If x > 0 and y < 0: [tex]\theta = 2\pi + tan^{-1}\frac{y}{x}[/tex];Calculating:
a) (4,2,-4)
[tex]\rho = \sqrt{4^{2}+2^{2}+(-4)^{2}}[/tex] = 6
[tex]\phi = cos^{-1}(\frac{-4}{6})[/tex]
[tex]\phi = cos^{-1}(\frac{-2}{3})[/tex]
For θ, choose 1st option:
[tex]\theta = tan^{-1}(\frac{2}{4})[/tex]
[tex]\theta = tan^{-1}(\frac{1}{2})[/tex]
b) (0,8,15)
[tex]\rho = \sqrt{0^{2}+8^{2}+(15)^{2}}[/tex] = 17
[tex]\phi = cos^{-1}(\frac{15}{17})[/tex]
[tex]\theta = tan^{-1}\frac{y}{x}[/tex]
The angle θ gives a tangent that doesn't exist. Analysing table of sine, cosine and tangent: θ = [tex]\frac{\pi}{2}[/tex]
c) (√2,1,1)
[tex]\rho = \sqrt{(\sqrt{2} )^{2}+1^{2}+1^{2}}[/tex] = 2
[tex]\phi = cos^{-1}(\frac{1}{2})[/tex]
[tex]\phi[/tex] = [tex]\frac{\pi}{3}[/tex]
[tex]\theta = tan^{-1}\frac{1}{\sqrt{2} }[/tex]
d) (−2√3,−2,3)
[tex]\rho = \sqrt{(-2\sqrt{3} )^{2}+(-2)^{2}+3^{2}}[/tex] = 5
[tex]\phi = cos^{-1}(\frac{3}{5})[/tex]
Since x < 0, use 2nd option:
[tex]\theta = \pi + tan^{-1}\frac{1}{\sqrt{3} }[/tex]
[tex]\theta = \pi + \frac{\pi}{6}[/tex]
[tex]\theta = \frac{7\pi}{6}[/tex]
Cilindrical coordinate describes a 3 dimension space: 2 distances (r and z) and 1 angle (θ). To express cartesian coordinates into cilindrical:
[tex]r=\sqrt{x^{2}+y^{2}}[/tex]
Angle θ is the same as spherical coordinate;
z = z
Calculating:
a) (4,2,-4)
[tex]r=\sqrt{4^{2}+2^{2}}[/tex] = [tex]\sqrt{20}[/tex]
[tex]\theta = tan^{-1}\frac{1}{2}[/tex]
z = -4
b) (0, 8, 15)
[tex]r=\sqrt{0^{2}+8^{2}}[/tex] = 8
[tex]\theta = \frac{\pi}{2}[/tex]
z = 15
c) (√2,1,1)
[tex]r=\sqrt{(\sqrt{2} )^{2}+1^{2}}[/tex] = [tex]\sqrt{3}[/tex]
[tex]\theta = \frac{\pi}{3}[/tex]
z = 1
d) (−2√3,−2,3)
[tex]r=\sqrt{(-2\sqrt{3} )^{2}+(-2)^{2}}[/tex] = 4
[tex]\theta = \frac{7\pi}{6}[/tex]
z = 3