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2 years ago

Find the eccentricity, b. identify the conic, c. give an equation of the directrix, and d. sketch the conic.

Mathematics

1 answer:

densk [106]2 years ago

6 0

Answer:

a) 10/3

b) hyperbola

c) x = ± 6/5

Step-by-step explanation:

a) A conic section with a focus at the origin, a directrix of x = ±p where p is a positive real number and positive eccentricity (e) has a polar equation:

$r=\frac{ep}{1\pm e*cos\theta}$

Given the conic equation: $r=\frac{12}{3-10cos\theta}$

We have to make it to be in the form $r=\frac{ep}{1\pm e*cos\theta}$ :

$r=\frac{12}{3-10cos\theta}\\\\multiply\ both\ sides\ by\ \frac{1}{3} \\\\r=\frac{12*\frac{1}{3}}{(3-10cos\theta)*\frac{1}{3}}\\\\r=\frac{12*\frac{1}{3}}{3*\frac{1}{3}-10cos\theta*\frac{1}{3}}\\\\r=\frac{4}{1-\frac{10}{3}cos\theta } \\\\r=\frac{\frac{10}{3}(\frac{6}{5} ) }{1-\frac{10}{3}cos\theta }$

Comparing with $r=\frac{ep}{1\pm e*cos\theta}$

e = 10/3 = 3.3333, p = 6/5

b) since the eccentricity = 3.33 > 1, it is a hyperbola

c) The equation of the directrix is x = ±p = ± 6/5

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On a coordinate plane, square P Q R S is shown. Point P is at (4, 2), point Q is at (8, 5), point R is at (5, 9), and point S is

sergey [27]

Answer:

(D)The midpoint of both diagonals is (4 and one-half, 5 and one-half), the slope of RP is 7, and the slope of SQ is Negative one-sevenths.

Step-by-step explanation:

Point P is at (4, 2),
Point Q is at (8, 5),
Point R is at (5, 9), and
Point S is at (1, 6)

Midpoint of SQ $=\frac{1}{2}(1+8,5+6)=(4.5,5.5)$

Midpoint of PR $=\frac{1}{2}(4+5,2+9)=(4.5,5.5)$

Now, we have established that the midpoints (point of bisection) are at the same point.

Two lines are perpendicular if the slope of one is the negative reciprocal of the other.

In option D

Slope of RP =7

Slope of SQ $=-\dfrac17$

Therefore, lines RP and SQ are perpendicular.

Option D is the correct option.

6 0

2 years ago

Find a polynomial function of degree 3 such that f(10)=17 and the zeros of f are 0, 5 and 8

fomenos

Step-by-step explanation:

Since f(0) = f(5) = f(8) = 0, we have f(x) = Ax(x - 5)(x - 8), where A is a real constant.

We know that f(10) = 17.

=> A(10)(10 - 5)(10 - 8) = 17

=> A(10)(5)(2) = 17

=> 100A = 17, A = 0.17.

Hence the answer is f(x) = 0.17x(x - 5)(x - 8).

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2 years ago

Three of the angles of a polygon are

Liono4ka [1.6K]

Answer:

three angles of a polygon are each 105.5,the sum of the angles in the polygon is 2520. find each of the other angles if they are equal to each other. For a polygon with n sides and n angles, the sum of the measures of all the interior angles equals (n-2)180 degrees. 16-3=13

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2 years ago

Round to the nearest ten thousand 905154

kolbaska11 [484]

You want to round 905,154 to the nearest ten-thousands place. The ten-thousands place in your number is shown by the bold underlined digit here:

9<em><u>0</u></em>5,154

    To round 905,154 to the nearest ten-thousands place...

    The digit in the ten-thousands place in your number is the 0. To begin the rounding, look at the digit one place to the right of the 0, or the 5, which is in the thousands place.

    Since the 5 is greater than or equal to 5, we'll round our number up by

        Adding 1 to the 0 in the ten-thousands place, making it a 1.

    and by changing all digits to the right of this new 1 into zeros.

The result is: 910,000.

So, 905,154 rounded to the ten-thousands place is 910,000.

5 0

2 years ago

Last year, 46% of business owners gave a holiday gift to their employees. A survey of business owners indicated that 35% plan to

DiKsa [7]

Answer:

a) Number = 60 *0.35=21

b) Since is a left tailed test the p value would be:

$p_v =P(Z$

c) If we compare the p value obtained and using the significance level given $\alpha=0.05$ we have $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can said that at 5% the proportion of business owners providing holiday gifts had decreased from the 2008 level.

We can use as smallest significance level 0.044 and we got the same conclusion.

Step-by-step explanation:

Data given and notation

n=60 represent the random sample taken

X represent the business owners plan to provide a holiday gift to their employees

$\hat p=0.35$ estimated proportion of business owners plan to provide a holiday gift to their employees

$p_o=0.46$ is the value that we want to test

$\alpha=0.05$ represent the significance level

Confidence=95% or 0.95

z would represent the statistic (variable of interest)

$p_v$ represent the p value (variable of interest)

Part a

On this case w ejust need to multiply the value of th sample size by the proportion given like this:

Number = 60 *0.35=21

2) Part b

We need to conduct a hypothesis in order to test the claim that the proportion of business owners providing holiday gifts had decreased from the 2008 level:

Null hypothesis: $p\geq 0.46$

Alternative hypothesis: $p < 0.46$

When we conduct a proportion test we need to use the z statisitc, and the is given by:

$z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}$ (1)

The One-Sample Proportion Test is used to assess whether a population proportion $\hat p$ is significantly different from a hypothesized value $p_o$ .

Calculate the statistic

Since we have all the info requires we can replace in formula (1) like this:

$z=\frac{0.35 -0.46}{\sqrt{\frac{0.46(1-0.46)}{60}}}=-1.710$

Statistical decision

It's important to refresh the p value method or p value approach . "This method is about determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.

The significance level provided $\alpha=0.05$ . The next step would be calculate the p value for this test.

Since is a left tailed test the p value would be:

$p_v =P(Z$

Part c

If we compare the p value obtained and using the significance level given $\alpha=0.05$ we have $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can said that at 5% the proportion of business owners providing holiday gifts had decreased from the 2008 level.

We can use as smallest significance level 0.044 and we got the same conclusion.

8 0

2 years ago