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3 years ago

Partition the interval [0,2] into 4 subintervals

Mathematics

1 answer:

Nataly_w [17]3 years ago

8 0

We will first divide the interval [0,2] into 4 equal length subintervals each of length -------> (2-0)/4=1/2.

<span> The four subintervals are </span>

<span>[0,1/2], [1/2,1], [1,3/2], [3/2,2] and the endpoints of these subintervals are </span>

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Find the center of mass of the wire that lies along the curve r and has density =4(1 sin4tcos4t)

dolphi86 [110]

The mass of the wire is found to be 40π√2 units.

To calculate the mass of the wire which runs along the curve r ( t ) with the density function δ=5.

The general formula is,

Mass = $\int_a^b \delta\left|r^{\prime}(t)\right| d t$

To find, we must differentiate this same given curve r ( t ) with respect to t to estimate |r'(t)|.

The given integration limits in this case are a = 0, b = 2π.

Now, as per the question;

The equation of the curve is given as;

r(t) = (4cost)i + (4sint)j + 4tk

Now, differentiate this same given curve r ( t ) with respect to t.

$\begin{aligned}\left|r^{\prime}(t)\right| &=\sqrt{(-4 \sin t)^2+(4 \cos t)^2+4^2} \\&=\sqrt{16 \sin ^2 t+16 \cos ^2 t+16} \\&=\sqrt{16\left(\sin t^2+\cos ^2 t\right)+16}\end{aligned}$

Further simplifying;

$\begin{aligned}&=\sqrt{16(1)+16} \\&=\sqrt{16+16} \\&=\sqrt{32} \\\left|r^{\prime}(t)\right| &=4 \sqrt{2}\end{aligned}$

Now, use integration to find the mass of the wire;

$\begin{aligned}&=\int_a^b \delta\left|r^{\prime}(t)\right| d t \\&=\int_0^{2 \pi} 54 \sqrt{2} d t \\&=20 \sqrt{2} \int_0^{2 \pi} d t \\&=20 \sqrt{2}[t]_0^{2 \pi} \\&=20 \sqrt{2}[2 \pi-0] \\&=40 \pi \sqrt{2}\end{aligned}$

Therefore, the mass of the wire is estimated as 40π√2 units.

To know more about density function, here

brainly.com/question/27846146

#SPJ4

The complete question is-

Find the mass of the wire that lies along the curve r and has density δ.

r(t) = (4cost)i + (4sint)j + 4tk, 0≤t≤2π; δ=5

5 0

1 year ago

A physical education department wanted a single test of upper body strength that was easy to administer. Dips on the parallel ba

Gennadij [26K]

Answer:

24.23 ; 13.47 ; 0.782 ; p value < 0.00001 ;7.45

Step-by-step explanation:

Given that :

ΣX = 3,416, ΣY = 1,899, SDX = 8.84, SDY = 4.70, ΣZXZY = 109.416

Sample size, N = 141

Mean of X:

£X / N = 3416 / 141 = 24.23

Mean of Y:

£Y / N = 1899 / 141 = 13.47

B.) Correlation between the 2 variables :

£ZXZY / N - 1

= 109.416 / 140

= 0.782

C.)

Level of significance and p value :

T = [Rsqrt(n-2)] ÷ sqrt(1 - R²)

T = [0.782 * sqrt(139)] ÷ sqrt(1-0.782^2)

T = 14.79

P value from Tscore calculator

Df = 141 - 2 = 139 ; α = 0.05

Pvalue = 0.00001

Pvalue < α ; Hence, a significant positive relationship exists.

To obtain regression model :

Slope = £ZXZY / SDX²

m = 109.416 / 8.84^2 = 1. 4

yintercept = meanY - slope*x

yintercept = 13.47 - 1.4*24.3

yintercept = - 20.55

Equation in slope intercept form:

y = mx + c

y = 1.4x - 20.55

For x = 20

y = 1.4(20) - 20.55

y = 7.45

5 0

3 years ago

Professor Liu gave the same quiz to the students in her morning class and in her afternoon class. The average (arithmetic mean)

natka813 [3]

Answer:

Afternoon class has more students.

Step-by-step explanation:

Let m be the number of students in the morning class and n be the number of students in the afternoon class.

The average score for the students in the morning class was 80, then the sum of their scores is $80m.$

The average score for the students in the afternoon class was 86, then the sum of their scores is $86n.$

The sum of the scores of both classes is

$80m+86n$

and the average score is

$\dfrac{80m+86n}{m+n}$

The average (arithmetic mean) score for the two classes combined was 84, then

$\dfrac{80m+86n}{m+n}=84\\ \\ 80m+86n=84m+84n\\ \\86n-84n=84m-80m\\ \\2n=4m\\ \\n=2m$

This means n is greater, so afternoon class has more students.

7 0

3 years ago

Solve the following system of equations graphically on the set of axes below Y= -2x - 7 Y= 3x - 2

elixir [45]

Answer:

x=−1 and y=−5

Step-by-step explanation:

hope this helps

3 0

3 years ago

Hector's service club is raising money by wrapping presents in the mall. The function f\left(x\right)=3xf(x)=3x describes the am

mestny [16]

Given:

The function f(x) describes the amount of money, in dollars, the club will earn for wrapping x presents.

$f(x)=3x$

To find:

The f(658).

Solution:

We have,

$f(x)=3x$

Substitute x=658 to find the value of f(658).

$f(658)=3(658)$

$f(658)=1974$

It means, the club will earn $1974 for wrapping 658 presents.

Therefore, $f(658)=1974$ .

7 0

2 years ago