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2 years ago

Resolucion de ese ejercicio por favor

Mathematics

1 answer:

sasho [114]2 years ago

7 0

Answer:

what?

Step-by-step explanation:

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Find, correct to four decimal places, the length of the curve of intersection of the cylinder 16x2 + y2 = 16 and the plane x + y

Yuri [45]

Let the curve C be the intersection of the cylinder

$16x^2+y^2=16$

and the plane

$x+y+z=1$

The projection of C on to the x-y plane is the ellipse

$16x^2+y^2=16$

To see clearly that this is an ellipse, le us divide through by 16, to get

$\frac{x^2}{1}+ \frac{y^2}{16}=1$

$\frac{x^2}{1^2}+ \frac{y^2}{4^2}=1$ ,

We can write the following parametric equations,

$x=cos(t), y=4sin(t)$

for

$0\le t \le 2\pi$

Since C lies on the plane,

$x+y+z=1$

it must satisfy its equation.

Let us make z the subject first,

$z=1-x-y$

This implies that,

$z=1-sin(t)-4cos(t)$

We can now write the vector equation of C, to obtain,

$r(t)=(cos(t),4sin(t),1-cos(t)-4sin(t))$

The length of the curve of the intersection of the cylinder and the plane is now given by,

$\int\limits^{2\pi}_0 {|r'(t)|} \, dt$

But

$r'(t)=(-sin(t),4cos(t),sin(t)-4cos(t))$

$|r'(t)|=\sqrt{(-sin(t))^2+(4cos(t))^2+(sin(t)-4cos(t))}$

$\int\limits^{2\pi}_0 {\sqrt{2sin^2(t)+32cos(t)-8sin(t)cos(t)} }\, dt=24.08778184$

Therefore the length of the curve of the intersection intersection of the cylinder and the plane is 24.0878 units correct to four decimal places.

6 0

3 years ago

Running times for 400 meters are Normally distributed for young men between 18 and 30 years of age with a mean of 93 seconds and

Luda [366]

Answer:

C. 45 and 141 seconds

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviation of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Mean = 93 seconds

Standard deviation = 16 seconds

99.7% of running times are approximately between:

By the Empirical rule, within 3 standard deviations of the mean, so between 3 standard deviations below the mean and 3 standard deviations above the mean

3 stnadard deviations below the mean

93 - 3*16 = 45 seconds

3 standard deviations above the mean

93 + 3*16 = 141 seconds

The correct answer is:

C. 45 and 141 seconds

3 0

3 years ago

Evan is earning some extra cash by mowing lawns. It takes Evan 6 ¾ hours to mow 3 lawns. The first lawn takes him 2 ⅞ hours and

denpristay [2]

Hope this helps the answer is 2 1/8 the picture explains how i did it :)

4 0

2 years ago

Factorise completely 12xy - 3x^2

LUCKY_DIMON [66]

Step-by-step explanation:

We need to factorise 3x

−12xy

Here we can take 3x common.

Thus we have 3x

−12xy=3x(x−4y)

Hence, factors are 3x,(x−4y).

4 0

2 years ago

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It takes 9 hours for 8 men to paint a room,

Leokris [45]

Answer:

6 people

Step-by-step explanation:

5 0

2 years ago