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2 years ago

Which of the following is an equation of the circle with a center at (-1,4) and a radius of 2√5 units? plss pahelp naman

Mathematics

1 answer:

Ksivusya [100]2 years ago

8 0

Answer:

Option A

Step-by-step explanation:

The standard form of an equation of a circle is represented by the formula $(x-h)^2+(y-k)^2 = r^2$ . Remember that $(h,k)$ is the center and $r^2$ is the radius squared.

So, the equation of the circle must be $(x+1)^2 +(y-4)^2 = 20$ . Complete the square to change the form of the equations listed in the options and find the one that is equal.

Let's try this with option A. Move the constants to the right side, then use the completing the square method to place the equation in standard form:

$x^2 + y^2 +2x -8y -3 = 0\\x^2 + y^2 +2x-8y = 3\\x^2 + 2x +y^2-8y = 3\\(x^2 +2x+1)+(y^2-8y +16)=3+1+16\\(x+1)^2 + (y-4)^2=20$

The end result matches with the equation determined before, so option A is the answer.

You might be interested in

What are the steps to answer -3(2r+7)=3

kumpel [21]

-3(2r+7)=3
distribute -3
-6r-21=3
add 21 to both sides, this causes the 21 on the left to cancel itself out.
-6r=24
divide each side by -6, this causes the -6 on the left side to cancel itself out.
r=-4

3 0

2 years ago

Read 2 more answers

Type the correct answer in the box. Use numerals instead of words. If necessary, use / for the fraction bar.

pantera1 [17]

Answer:

-5/2 x -33/4

Step-by-step explanation:

(-11/2 x + 3) -2 (-11/4 x -5/2)

(-11/2 x + 3/1) -2 (-11/4 x -5/2)

The LCM of 2 and 1 is 2, and the LCM of 4 and 2 is 4.

(-11/2 x + 6/2) -2 (-11/4 x -20/4)

( -5/2x) -2 (-31/4)

-5/2x -2 -31/4

-5/2x -2/1 -31/4

LCM of -2 -31/4 is 4

-2/4 -31/4

-33/4

-5/2x -33/4 in simplest form.

4 0

2 years ago

Nationally, patients who go to the emergency room wait an average of 7 hours to be admitted into the hospital. Do patients at ru

valina [46]

For this study, we should use t-test and the null and alternative hypotheses would be given by H₀: μ = 7 and H₁: μ < 7.
The test statistic is -1.941 and the p-value (0.0381) is <u>greater than</u> α = 0.01.
Based on this, we should <u>fail to reject</u> the null hypothesis.
Thus, the final conclusion is that the data suggest the population mean is not significantly lower than 7 at α = 0.01, so there is statistically insignificant evidence to conclude that the population mean waiting time to be admitted into the hospital from the emergency room for patients at rural hospitals is equal to 7 hours.

<h3>What is a null hypothesis?</h3>

A null hypothesis (H₀) can be defined the opposite of an alternate hypothesis (H₁) and it asserts that two (2) possibilities are the same.

<h3>How to calculate value of the test statistic?</h3>

The test statistics can be calculated by using this formula:

$t=\frac{x\;-\;u}{\frac{\delta}{\sqrt{n} } }$

<u>Where:</u>

x is the sample mean.

u is the mean.

is the standard deviation.

n is the number of hours.

For this study, we should use t-test and the null and alternative hypotheses would be given by:

H₀: μ = 7

H₁: μ < 7

$t=\frac{6.3\;-\;7}{\frac{1.3}{\sqrt{13} } }\\\\t=\frac{-0.7}{\frac{1.3}{3.6056 } }$

t = -0.7/0.3606

t = -1.941.

For the p-value, we have:

P-value = P(t < -1.9412)

P-value = 0.0381.

Therefore, the p-value (0.0381) is <u>greater than</u> α = 0.01. Based on this, we should <u>fail to reject</u> the null hypothesis.

Thus, the final conclusion is that the data suggest the population mean is not significantly lower than 7 at α = 0.01, so there is statistically insignificant evidence to conclude that the population mean waiting time to be admitted into the hospital from the emergency room for patients at rural hospitals is equal to 7 hours.

Read more on null hypothesis here: brainly.com/question/14913351

#SPJ1

4 0

1 year ago

Six hundred paving stones were examined for cracks, and 20 were found to be cracked. The same 600 stones were then examined for

spin [16.1K]

Answer:

a) probability that is cracked=1/30 (3.33%)

b) probability that is discoloured = 29/600 (4.83%)

c) probability that is cracked and discoloured = 11/600 (1.83%)

Step-by-step explanation:

assuming that each stone is equally likely to be chosen then defining the events C= the stone is cracked , D= the stone is discoloured , N= the stone is neither cracked or discoloured, then

P(C)= number of favourable outcomes/total number of outcomes = 20 stones/600 stones = 1/30 (3.33%)

P(D)= number of favourable outcomes/total number of outcomes = 29 stones/600 stones = 29/600 (4.83%)

the probability that is discoloured and cracked is P(C∩D) , where

P(C∪D)=P(C) + P(D)-P(C∩D)

and

P(C∪D)= 1- P(N)

thus

1- P(N)=P(C) + P(D)-P(C∩D)

P(C∩D)= P(N)+P(C)+P(D) -1

replacing values

P(C∩D)= P(N)+P(C)+P(D)=562/600 + 20/600 + 29/600 -1= 611/600 -1 = 11/600

thus

P(C∩D)= 11/600 (1.83%)

3 0

2 years ago

---------------------------------------what is pi

nata0808 [166]

Pi is the ratio of the diameter to the circumference
circumference/diameter=pi
that's why c=pid or c=2pir

some digits are <span>3.14159265358979323846264338327950288419716939
937510582097494...</span>

7 0

2 years ago