Can somebody plz help me Q 4-5-6 Plz and thank you

Please help I’m having trouble with this question!

mezya [45]

ok thanks for letting me know you need help

4 0

2 years ago

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

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

or

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

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

At leslie's school the ratio of boys and girls is 11 to 12 at marks school the ratio of boys girls is 41 to 48 if both schools h

Softa [21]

Answer: B. There are more boys at Mark's school than at Leslie's school because the ratio 41 to 48 is greater than the ratio 11 to 12.

Step-by-step explanation:

Here are the options:

A There are more boys at Mark's school than at Leslie's school because the ratio 11 to 12 is greater than the ratio 41 to 48.

B. There are more boys at Mark's school than at Leslie's school because the ratio 41 to 48 is greater than the ratio 11 to 12.

C. There are more boys at Leslie's school than at Mark's school because the ratio 41 to 48 is greater than the ratio 11 to 12.

At leslie's school the ratio of boys and girls is 11 to 12. This implies that the fraction of boys in the school to total students will be:

= 11/(11 + 12) = 11/23 = 0.4783

At Marks school the ratio of boys to girls is 41 to 48. Thus implies that the fraction of boys in the school to total students will be:

= 41 / (41 + 48) = 41/85= 0.4824

Based on the calculation, we can deduce that there are more boys at Mark's school than at Leslie's school because the ratio 41 to 48 is greater than the ratio 11 to 12.

6 0

2 years ago

Find dy dx for y=1/ <img src="https://tex.z-dn.net/?f=%20%5Csqrt%7Bx%7D%20" id="TexFormula1" title=" \sqrt{x} " alt=

Iteru [2.4K]

please check the attachment

7 0

2 years ago

An airline runs a commuter flight between Portland, Oregon, and Seattle, Washington, which are 145 miles apart. An increase of 2

pychu [463]

The speed of the airplane is the ratio of the distance to the time

The initial average speed of the airplane is approximately 110.8 mph

Reason:

Given parameters are;

The distance between Portland Oregon and Seattle Washington = 145 miles

The decrease in travel time when the speed is increase by 20 mph = minutes

The initial speed of the airplane, v = Required;

Solution;

$t = \dfrac{145}{v}$

$t - \dfrac{12}{60} = \dfrac{145}{v + 20}$

Therefore;

$\dfrac{145}{v} - \dfrac{12}{60} = \dfrac{145}{v + 20}$

Which gives;

$\dfrac{145}{v + 20} - \dfrac{145}{v} + \dfrac{12}{60} = 0$

Therefore

0.2·v² + 4·v - 2,900 = 0

v ≈ ±110.8 mph

The initial average speed of the airplane, v≈ ± 110.8 mph

Learn more here:

brainly.com/question/11365874

4 0

2 years ago