Answers
Answer:
Step-by-step explanation:
I honestly have no idea what you mean by answer by formula, but I'm going to give it my best. I began by squaring both sides to get:
(a² - b²) tan²θ = b² and then distributed to get:
a² tan²θ - b² tan²θ = b² and then got the b terms on the side to get:
a² tan²θ = b² + b² tan²θ and then changed the tans to sin/cos to get:
[tex]\frac{a^2sin^2\theta}{cos^2\theta}=b^2+\frac{b^2sin^2\theta}{cos^2\theta}[/tex] and isolated the sin-squared on the left to get:
[tex]a^2sin^2\theta=cos^2\theta(b^2+\frac{b^2sin^2\theta}{cos^2\theta})[/tex] and distributed to get:
***[tex]a^2sin^2\theta=b^2cos^2\theta+b^2sin^2\theta[/tex]*** and factored the right side to get:
[tex]a^2sin^2\theta=b^2(sin^2\theta+cos^2\theta)[/tex] and utilized a trig Pythagorean identity to get:
[tex]a^2sin^2\theta=b^2(1)[/tex] and then solved for sinθ in the following way:
[tex]sin^2\theta=\frac{b^2}{a^2}[/tex] so
[tex]sin\theta=\frac{b}{a}[/tex] This, along with the *** expression above will be important. I'm picking up at the *** to solve for cosθ:
[tex]a^2sin^2\theta=b^2cos^2\theta+b^2sin^2\theta[/tex] and get the cos²θ alone on the right by subtracting to get:
[tex]a^2sin^2\theta-b^2sin^2\theta=b^2cos^2\theta[/tex] and divide by b² to get:
[tex]\frac{a^2sin^2\theta}{b^2}-sin^2\theta=cos^2\theta[/tex] and factor on the left to get:
[tex]sin^2\theta(\frac{a^2}{b^2}-1)=cos^2\theta[/tex] and take the square root of both sides to get:
[tex]\sqrt{sin^2\theta(\frac{a^2}{b^2}-1) }=cos\theta[/tex] and simplify to get:
[tex]\frac{sin\theta}{b}\sqrt{a^2-b^2}=cos\theta[/tex] and go back to the identity we found for sinθ and sub it in to get:
[tex]\frac{\frac{b}{a} }{b}\sqrt{a^2-b^2}=cos\theta[/tex] and simplifying a bit gives us:
[tex]\frac{1}{a}\sqrt{a^2-b^2}=cos\theta[/tex]
That's my spin on things....not sure if it's what you were looking for. If not.....YIKES
Related Questions
72a^7/-9 as a monomial
Answers
Answer:
− 8 a ^7
Step-by-step explanation:
See picture for steps :)
Which values of x are solutions to this equation? -1/2x^2 + 5x = 8
A) -2
B) 2
C) -8
D) -1.5
E) 11.5
F) 8
Answers
Answer:
2, 8
Step-by-step explanation:
-1/2x^2 + 5x = 8
-x^2 + 10x = 16 (Multiplying both sides of the equation by 2)
-x^2 + 10x - 16 = 0
x^2 - 10x + 16 = 0 (changing the signs)
x^2 -2x -8x +16 = 0
x (x-2) -8 (x-2) = 0
(x-2) (x-8)
x-2 = 0
x = 2
or
x -8 = 0
x = 8
Answer from Gauthmath
The values of x are solutions to this equation that is 2, 8
What is an equation?An equation is an expression that shows the relationship between two or more numbers and variables.
We are given that the equation as;
-1/2x² + 5x = 8
-x² + 10x = 16
Now Multiplying both sides of the equation by 2;
-x² + 10x - 16 = 0
Or
x² - 10x + 16 = 0
x² -2x -8x +16 = 0
x (x-2) -8 (x-2) = 0
(x-2) (x-8)
The solution are;
x-2 = 0
x = 2
or
x -8 = 0
x = 8
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ASAP PLSSSSSSSS TYYYYYY
Answers
Answer:
20% of students prefer to go to the aquarium
50% of teachers prefer to go to the aquarium
Step-by-step explanation:
1.
8 students prefer the aquarium out of 40 students.
Set up an equation:
Variable x = percentage of students
8/40 = x/100
Cross multiply:
8 × 100 = 40 × x
800 = 40x
20 = x
Divide:
20%
Check your work:
40 students × 20%
Convert percentage into decimal:
40 × 0.20
8
8 students prefered the aquarium so this is correct!
2.
5 teachers prefer the aquarium out of 10 teachers.
Set up an equation:
Variable x = percentage of teachers
5/10 = x/100
5 × 100 = 10 × x
500 = 10x
50 = x
50%
Check your work:
10 × 0.50
5
Correct!
PLEASE HELPPPPPPPPP!!!!!!!!!!!
Answers
How does the graph of this function compare with the graph of the parent function, y=1/x? It is shifted right 5 units and up 2 units from the parent function. It is shifted left 5 units and up 2 units from the parent function. It is shifted right 5 units and down 2 units from the parent function. It is shifted left 2 units and down 5 units from the parent function. It is shifted right 2 units and up 5 units from the parent function. It is shifted left 2 units and up 5 units from the parent function.
Answers
Answer:
It is shifted left 5 units and up 2 units from the parent function.
Step-by-step explanation:
Given
[tex]y = \frac{1}{x}[/tex]
[tex]y' = \frac{1}{x+5} + 2[/tex]
Required
Compare both functions
First, translate y, 5 units left.
The rule is:
[tex](x,y) \to (x + 5,y)[/tex]
So, we have:
[tex]y = \frac{1}{x}[/tex]
[tex]y_1 = \frac{1}{x + 5}[/tex]
Next, translate y1, 2 units up.
The rule is:
[tex](x,y) \to (x,y+2)[/tex]
So, we have:
[tex]y' = y_1 + 2[/tex]
[tex]y' = \frac{1}{x + 5} + 2[/tex]
Hence, the transformation is:
5 units left and 2 units up
Answer:
b
Step-by-step explanation:
solving systems by substitution
how would you you find the answer for
-5x + y = -2
-3x+6y=-12 ? having some issues with how to this
Answers
9514 1404 393
Answer:
(x, y) = (0, -2)
Step-by-step explanation:
When solving by substitution, you usually want to find an expression for one of the variables in terms of the other. So, the first thing you look for is an equation that has a coefficient of 1 or -1 on one of the variables. Recognizing that the second equation's terms all have a common factor of 3, you basically have two choices.
Substitute for yUsing equation 1, you can write an expression for y:
y = 5x -2 . . . . . . add 5x to both sides
Then substituting this into the original equation 2, you have ...
-3x +6(5x -2) = -12
27x -12 = -12 . . . . . . . simplify
27x = 0 . . . . . . . . . add 12
x = 0 . . . . . . . . . divide by 27
y = 5(0) -2 = -2 . . . . find y using the expression for substitution
The solution is (x, y) = (0, -2).
__
Substitute for xIf you decide you'd rather substitute for x, you can solve the second equation easily for x.
-3x +6y = -12
x -2y = 4 . . . . . . divide by -3
x = 2y +4 . . . . . . add 2y
Substituting for x in the first equation gives ...
-5(2y +4) +y = -2 . . . . substitute for x
-9y -20 = -2 . . . . . . . simplify
-9y = 18 . . . . . . . . . add 20
y = -2 . . . . . . . . . . . divide by -9
x = 2(-2) +4 = 0 . . . . find x using the expression for substitution
The solution is (x, y) = (0, -2).
_____
Additional comment
In some cases, there are no variables that have a coefficient of ±1, so you just need to "bite the bullet" and deal with the resulting fractions.
Example:
solve for y: -5x +2y = -2
2y = 5x -2
y = 5/2x -1 . . . . expression used to substitute for y
Of course, you can multiply the equation after substitution by 2 to eliminate fractions, or just work the problem as is. The point of looking for coefficients of ±1 is to avoid having to do arithmetic with fractions. It can help avoid errors to work with integers, but ultimately the method is the same regardless of the form of the numbers.
__
You don't always have to substitute for the "bare" variable. Sometimes it can save steps to substitute for expressions instead of variables. If our system of equations were ...
-5x +2y = -2-3x +6y = -12You can substitute into the second equation for (2y). In that case, the second equation becomes ...
-3x +3(2y) = -12
-3x +3(5x-2) = -12 . . . . . . where 2y = 5x -2
find the value of x²-6x+13 when x=3+2i
Answers
Answer:
18
Step-by-step explanation:
x squared -6 +13
5 squared-6×3+2+13
25-20+13
5+13
=18
Given that 3x-7y=-27 and 5x+9y=17. Find the values of x and y that satisfy both equations, using elimination method.
Answers
here's the answer to your question
solve for x
3x-7y=-27
5x+9y=17
multiply 9, 7
27x -63y =-243
35x +63y = 119
add and cancel y out
62x = -124
x = -2
plug in x
-6-7y=-27
-7y=-21
y = 3
answer:
y = 3
x = -2
The salt content in snack bags of pretzels is Normally distributed, with a mean of 180 mg and a standard deviation of 15 mg. Eighty four percent of bags have a salt content higher than which value?
Find the z-table here.
165.2 mg
179.2 mg
187.0 mg
194.9 mg
I think its (A), 165.2mg
Answers
Answer: Yes you are correct. The answer is choice A
============================================================
Explanation:
If you used the z-table, you should find that P(Z < 1) = 0.84 approximately.
So by symmetry, P(Z > -1) = 0.84 approximately as well.
We'll convert the z score z = -1 into its corresponding x score
z = (x-mu)/sigma
-1 = (x-180)/15
-15 = x-180
x-180 = -15
x = -15+180
x = 165
We don't land on any of the answer choices listed, but we get fairly close to 165.2, which is choice A. So you are correct.
I have a feeling that the table you have is probably more accurate than the one I'm using, so it's possible that you'd land exactly on 165.2 when following the steps above.
Answer:
194.9
Step-by-step explanation:
ON EDG
An investment of $8,120 is earning interest at the rate of 5.8% compounded quarterly over 11 years. How much
interest is earned on the investment? Show your work.
Answers
Answer:
5180.56 Dollars...........
Family Video stocks 1003 drama movies, 518 science fiction movies and
253 children's movies. How many more drama titles than children's
titles does Family Video have in stock?
Answers
Answer:
There are 750 more drama movies that children's movies.
Step-by-step explanation:
There are 1003 drama movies, and 253 children's movies.
1003 - 253 = 750
If ABCD is dilated by a factor of 3, the
coordinate of D' would be:
4
с
3
B
2
1
-5
-4
-3
-2
-1 0
1
N
3
4
5
DAN
- 1
-2
D
-3
D' = ([?], [ ]
Enter
Pls help me
Answers
Answer:
(6,-6)
Step-by-step explanation:
First let's identify the current coordinates of D
It appears that D is located at (2 , -2)
Now let's find the coordinate of D if it were dilated by a scale factor of 3.
To find the coordinates of a point after a dilation you simply multiply the x and y values of the pre image coordinates by the scale factor
In this case the scale factor is 3 and the coordinates are (2,-2)
That being said let's apply the dilation rule
Current coordinates: (2,-2)
Scale factor:3
Multiply x and y values by scale factor
(2 * 3 , -2 * 3) --------> (6 , -6)
The coordinates of D' would be (6,-6)
The manufacturer of cans of salmon that are supposed to have a net weight of 6 ounces tells you that the net weight is actually a normal random variable with a mean of 6.05 ounces and a standard deviation of .18 ounces. Suppose that you draw a random sample of 36 cans.
a. Find the probability that the mean weight of the sample is less than 5.97 ounces.
b. Suppose your random sample of 36 cans of salmon produced a mean weight that is less than 5.97 ounces. Comment on the statement made by the manufacturer.
Answers
Answer:
a) 0.0038 = 0.38% probability that the mean weight of the sample is less than 5.97 ounces.
b) Given a mean of 6.05 ounces, it is very unlikely that a sample mean of less than 5.97 ounces, which means that the true mean must be recalculated.
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
Mean of 6.05 ounces and a standard deviation of .18 ounces.
This means that [tex]\mu = 6.05, \sigma = 0.18[/tex]
Sample of 36:
This means that [tex]n = 36, s = \frac{0.18}{\sqrt{36}} = 0.03[/tex]
a. Find the probability that the mean weight of the sample is less than 5.97 ounces.
This is the p-value of z when X = 5.97. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{5.97 - 6.05}{0.03}[/tex]
[tex]Z = -2.67[/tex]
[tex]Z = -2.67[/tex] has a p-value of 0.0038.
0.0038 = 0.38% probability that the mean weight of the sample is less than 5.97 ounces.
b. Suppose your random sample of 36 cans of salmon produced a mean weight that is less than 5.97 ounces. Comment on the statement made by the manufacturer.
Given a mean of 6.05 ounces, it is very unlikely that a sample mean of less than 5.97 ounces, which means that the true mean must be recalculated.
How long will it take for money to double if it is invested at 7% compounded monthly?
Answers
About 10.3 years
Solve for Y equals -2 over 3x minus 1
Answers
Answer:
y=-\frac{2}{3}\approx -0.666666667
Factorise: 25x^2 - 1/49
Answers
Answer:
[tex] (5x + \frac{1}{7} )(5x - \frac{1}{7} )[/tex]Step-by-step explanation:
Given,
[tex] {25x}^{2} - \frac{1}{49} [/tex]
[tex] = {(5x)}^{2} - {( \frac{1}{7}) }^{2} [/tex]
Since,
[tex] {x}^{2} - {y}^{2} = (x + y)(x - y)[/tex]
Then,
[tex] = (5x + \frac{1}{7} )(5x - \frac{1}{7} )(ans)[/tex]
Which of the following graphs represents the line that passes through (–2, –3) and has a slope of 2/3?
Answers
Fourth graph
Step-by-step explanation:
It passes through the point (-2, -3) and has a slope of 2/3
Answer:
Step-by-step explanation:
A hospital director is told that 54% of the emergency room visitors are insured. The director wants to test the claim that the percentage of insured patients is under the expected percentage. A sample of 120 patients found that 60 were insured. Find the value of the test statistic. Round your answer to two decimal places.
Answers
Answer:
Z -0.879173965
Step-by-step explanation:
Z -0.879173965
ρ 0.5
π 0.54
n 120
The value of the test statistic is the z-score z = -0.88
What is a z-score?The relationship between a value and the mean of a set of values is expressed numerically by a Z-score. The Z-score is computed using the standard deviations from the mean. A Z-score of zero indicates that the data point's score and the mean score are identical.
The Z-score is calculated using the formula:
z = (x - μ)/σ
where z: standard score
x: observed value
μ: mean of the sample
σ: standard deviation of the sample
Given data ,
Let the test statistic value be represented as z
Now , the probability of emergency room visitors are insured is q = 0.54
The total number of patients n = 120
The number of patients that were insured = 60
So , the percentage of people that were insured p = 60/120 = 0.5
Now , test statistic value z = ( p - q ) / [ √ ( q ( 1 - q )/n² ]
The value of z score is
z = [ 0.5 - 0.54 ] / √ 0.54 ( 1 - 0.54 ) / 120²
On simplifying the equation , we get
The value of z score is z = -0.88
Hence , the test statistic is z = -0.88
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Your small business spent $40 on food and another $60 on materials. Then, you sold an item for $120, but you had to pay a $90 service fee. Finally, you were given a refund from the Internal Revenue Service (IRS) for $70. If the expression describing these transactions is the following, then how does it evaluate?
Answers
Answer:
40$+60$=100$ spent
120$sold
90$ payed
70$ refund
120 (sold) -90 (payed) =30+70 (refund) =100$ (profit)
Step-by-step explanation:
You spent 100$
And you sold and got 120 but you payed 90$ from 120$ money left is 30$
Then they refunded you (pay back the money (give you the money ))
So the money that your left with is 30$ and the refund money is 70$
So add the money that your left with is gives you 100$
Find f′ in terms of g′
f(x)=x2g(x)
Select one:
f′(x)=2xf′(x)+2xg′(x)
f′(x)=2xg′(x)
f′(x)=2x+g′(x)
f′(x)=x2g(x)+2x2g′(x)
f′(x)=2xg(x)+x2g′(x)
Answers
9514 1404 393
Answer:
(e) f′(x)=2xg(x)+x²g′(x)
Step-by-step explanation:
The product rule applies.
(uv)' = u'v +uv'
__
Here, we have u=x² and v=g(x). Then u'=2x and v'=g'(x).
f(x) = x²·g(x)
f'(x) = 2x·g(x) +x²·g'(x)
From a club of 24 people, in how many ways can a group of four members be selected to attend a conference?
Answers
Answer:
255,024
Step-by-step explanation:
24 x 23 x 22 x 21
24 options for the first member
23 options for the second member
22 options for the third member
21 options for the last member
Instructions: State what additional information is required in order
to know that the triangles in the image below are congruent for the
reason given
Reasory. AAS Postulate
Answers
Answer:
YWX = DFE
Step-by-step explanation:
AAS means angle angle side. so, we need 2 angles and 1 side.
we have 1 side and one angle confirmed.
so, we need one of the other two angles (W or Y vs. F or D) confirmed.
they probably want W and F as answer, as Y and D would make it a special case of AAS : ASA.
Use the compound interest formula to find the annual interest rate, r, if in 2 years an investment of 4,000 grows to 4410 The rate is %.
Answers
Answer:
5%
Step-by-step explanation:
Bank amount=PA*(1+r/100)^t
4410=4000*(1+x/100)^2
1.05=(1+x/100), x=5%
help with summer school
Answers
Answer:
19
Step-by-step explanation:
3a -2^3 ÷b
Let a = 7 and b = 4
3*7 -2^3 ÷4
PEMDAS says exponents first
3*7 -8 ÷4
Multiply and divide from left to right
21 - 2
Subtract
19
A professor wondered if there was a difference in the proportion of students who dropped math classes between females and males. The professor randomly selected 20 math classes around campus and recorded the gender of the individual and whether or not a student enrolled in the class at the beginning of the term dropped the class at some point during the term. Assuming all conditions are satisfied, which of the following tests should the researcher use? Choose the correct answer below.
a) Chi-square goodness of fit test
b) two-sample z-test for proportions C
c) paired t-test
d) one-sample z-test for proportions
e) two-sample t-test
Answers
Answer:
b) two-sample z-test for proportions
Step-by-step explanation:
The most appropriate test to use for the research hypothesis stated above is the two sample z-test for proportions, this is because, the experiment has two independent groups (male and female) with the result of each group not affecting the result of the other. The experiment clearly stses that, it is to estimate the difference in proportion, hence, it is a test of proportions rather than mean. Also when performing, a two sample tests of proportion, the Z distribution is used.
The graph shows the distribution of lengths of songs (in seconds). The distribution is approximately Normal, with a mean of 227 seconds and a standard deviation of 31 seconds.
A graph titled Song length has length (seconds) on the x-axis, going from 103 to 351 in increments of 31. The highest point of the curve is at 227.
What percentage of songs have lengths that are within 31 seconds of the mean?
34%
68%
95%
99.7%
Answers
its everything between 196 and 258 seconds (at max 31secs away from the mean). imagine straight upward lines separating this area from the rest.
34% would be way too low, 95 and above way too much.
only 68% is remotely plausible.
The sum of three numbers is 124
The first number is 10 more than the third.
The second number is 4 times the third. What are the numbers?
Answers
Answer:
182/3,3 8/3, 152/3
Step-by-step explanation:
a+b+c=124
a trừ c= 10
4b=c
Answer:
a=29,b=79,c=19
Step-by-step explanation:
a=c+10
b=4c
=> a+b+c=c+10+4c+c=124
=> c=19
=> a= 29, b=79
A community swimming pool is a rectangular prism that is 30 feet long, 12 feet wide, and 5 feet deep. The wading pool is half as long, half as deep, and the same width as the larger pool.
How many times greater is the volume of the swimming pool than the volume of the wading pool?
Answers
A baseball team plays in a stadium that holds 58000 spectators. With the ticket price at $12 the average attendance has been 25000. When the price dropped to $9, the average attendance rose to 29000. Assume that attendance is linearly related to ticket price.
Required:
a. Find the demand function p(x), where x is the number of the spectators.
b. How should ticket prices be set to maximize revenue?
Answers
Answer:
We need to assume that the relationship is linear.
a) Remember that a linear relation is written as:
y = a*x + b
then we will have:
p(x) = a*x + b
where a is the slope and b is the y-intercept.
If we know that the line passes through the points (a, b) and (c, d), then the slope can be written as:
y = (d - b)/(c - a)
In this case, we know that:
if the ticket has a price of $12, the average attendance is 25,000
Then we can define this with the point:
(25,000 , $12)
We also know that when the price is $9, the attendance is 29,000
This can be represented with the point:
(29,000, $9)
Then we can find the slope as:
a = ($9 - $12)/(29,000 - 25,000) = -$3/4,000 = -$0.00075
Then the equation is something like:
y = (-$0.00075)*x + b
to find the value of b we can use one of the known points.
For example, the point (25,000 , $12) means that when x = 25,000, the price is $12
then:
$12 = (-$0.00075)*25,000 + b
$12 = -$18.75 + b
$12 + $18.75 = b
$30.75 = b
Then the equation is:
p(x) = (-$0.00075)*x + $30.75
b) We want to find the ticket price such that it maximizes the revenue.
The revenue will be equal to the price per ticket, p(x) times the total attendance, x.
Then the revenue can be written as:
r(x) = x*p(x) = x*( (-$0.00075)*x + $30.75 )
r(x) = (-$0.00075)*x^2 + $30.75*x
So we want to find the maximum revenue.
Notice that this is a quadratic equation with a negative leading coefficient, thus the maximum will be at the vertex.
Remember that for an equation like:
y = a*x^2 + bx + c
the x-value of the vertex is:
x = -b/2a
Then in our case, the x-value will be:
x = -$30.75/(2*(-$0.00075)) = 20,500
Then the revenue is maximized for x = 20,500
And the price for this x-vale is given by:
p( 20,500) = (-$0.00075)*20,500 + $30.75 = $15.375
which should be rounded to $15.38
In 2012 your car was worth $10,000. In 2014 your car was worth $8,850. Suppose the value of your car decreased at a constant rate of change. Define a function f to determine the value of your car (in dollars) in terms of the number of years t since 2012.
Answers
Answer:
The function to determine the value of your car (in dollars) in terms of the number of years t since 2012 is:
[tex]f(t) = 10000(0.9407)^t[/tex]
Step-by-step explanation:
Value of the car:
Constant rate of change, so the value of the car in t years after 2012 is given by:
[tex]f(t) = f(0)(1-r)^t[/tex]
In which f(0) is the initial value and r is the decay rate, as a decimal.
In 2012 your car was worth $10,000.
This means that [tex]f(0) = 10000[/tex], thus:
[tex]f(t) = 10000(1-r)^t[/tex]
2014 your car was worth $8,850.
2014 - 2012 = 2, so:
[tex]f(2) = 8850[/tex]
We use this to find 1 - r.
[tex]f(t) = 10000(1-r)^t[/tex]
[tex]8850 = 10000(1-r)^2[/tex]
[tex](1-r)^2 = \frac{8850}{10000}[/tex]
[tex](1-r)^2 = 0.885[/tex]
[tex]\sqrt{(1-r)^2} = \sqrt{0.885}[/tex]
[tex]1 - r = 0.9407[/tex]
Thus
[tex]f(t) = 10000(1-r)^t[/tex]
[tex]f(t) = 10000(0.9407)^t[/tex]
