answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
tatiyna
2 years ago
12

Let c be the curve of intersection of the parabolic cylinder x2 = 2y, and the surface 3z = xy. find the exact length of c from t

he origin to the point (2, 2, 4/3).
Mathematics
1 answer:
Mandarinka [93]2 years ago
3 0
Parameterize the intersection by setting x(t)=t, so that

x^2=2y\iff y=\dfrac{x^2}2\implies y(t)=\dfrac{t^2}2
3z=xy\iff z=\dfrac{xy}3\implies z(t)=\dfrac{t^3}6

The length of the path C is then given by the line integral along C,

\displaystyle\int_C\mathrm dS

where \mathrm dS=\sqrt{\left(\dfrac{\mathrm dx}{\mathrm dt}\right)^2+\left(\dfrac{\mathrm dy}{\mathrm dt}\right)^2+\left(\dfrac{\mathrm dz}{\mathrm dt}\right)^2}\,\mathrm dt. We have

\dfrac{\mathrm dx}{\mathrm dt}=1
\dfrac{\mathrm dy}{\mathrm dt}=t
\dfrac{\mathrm dz}{\mathrm dt}=\dfrac{t^2}2

and so the line integral is

\displaystyle\int_{t=0}^{t=2}\sqrt{1^2+t^2+\dfrac{t^4}4}\,\mathrm dt

This result is fortuitous, since we can write

1+t^2+\dfrac{t^4}4=\dfrac14(t^4+4t^2+4)=\dfrac{(t^2+2)^2}4=\left(\dfrac{t^2+2}2\right)^2

and so the integral reduces to

\displaystyle\int_{t=0}^{t=2}\frac{t^2+2}2\,\mathrm dt=\dfrac{10}3
You might be interested in
If PQ=RS, which of the following must be true?
maw [93]

<u>Answer:</u>

If PQ=RS then PQ and RS have the same length. Hence option D is correct

<u>Solution:</u>

Given that, pq = rs  

And, we have to find which of the given options are true.

<u><em>a) pq and rs form a straight angle </em></u>

We can’t decide the angle in between pq and rs just by the statement pq = rs.

So this statement is false.

<u><em>b) pq and rs form a zero angle. </em></u>

We can’t decide the angle in between pq and rs just by the statement pq = rs.

So this statement is false.

<u><em>c) pq and rs are same segment. </em></u>

If two things equal then there is no condition that both represents a single item.

So this statement is false.

<u><em>d) pq and rs have the same length </em></u>

As given that pq = rs, we can say that they will have the same length  

Hence, option d is true.

4 0
2 years ago
Each day Julian gives his dog, Banjo, 3 liters of water and 500 grams of food. Julian wants to track the total amount of the foo
Masteriza [31]

Answer:

The correct answer would be option C.

Step-by-step explanation:

Since he gives the dog 3 liters of water and 500 grams of food a day we know that on the fifth day the dog will have gotten 15 liters of water and 2,500 grams of food.

4 0
2 years ago
Read 2 more answers
Identify two numbers less than 20 with the most factors
Anastaziya [24]

<u>Answer</u>

18 and 12


<u>Explanation</u>

Factor is a number or algebraic expression that divides another number or expression evenly that is with no remainder.

Odd number have few factors so the can't be the answer.

WE are going to try the even numbers.

18 ⇒ 18, 9, 6, 3, 2, 1

16 ⇒ 16, 8, 4, 2, 1

12 ⇒ 12, 6, 4, 3, 2, 1

10 ⇒ 10, 5, 2, 1

Other number less than 10 has factors less than 5.

It can be seen from above that 18 and 12 have the most factors.

3 0
2 years ago
Read 2 more answers
A pendulum is set swinging. its first oscillation is through 30 and each succeeding oscillation is through 95% of the angle of t
Marat540 [252]

<u>Answer-</u>

<em>After 76 swings</em><em> the angle through which it swings less than 1°</em>

<u>Solution-</u>

From the question,

Angle of the first of swing = 30° and then each succeeding oscillation is through 95% of the angle of the one before it.

So the angle of the second swing = (30\times \frac{95}{100})^{\circ}

Then the angle of third swing = (30\times (\frac{95}{100})^2)^{\circ}

So, this follows a Geometric Progression.

(30,\ 30\cdot \frac{95}{100},\ 30\cdot (\frac{95}{100})^2............,0)

a = The initial term = 30

r = Common ratio = \frac{95}{100}

As we have to find the number swings when the angle swept by the pendulum is less than 1°.

So we have the nth number is the series as 1, applying the formula

T_n=ar^{n-1}

Putting the values,

\Rightarrow 1=30(\frac{95}{100})^{n-1}

\Rightarrow \frac{1}{30} =(\frac{95}{100})^{n-1}

Taking logarithm of both sides,

\Rightarrow \log \frac{1}{30} =\log (\frac{95}{100})^{n-1}

\Rightarrow \log \frac{1}{30} =(n-1)\log (\frac{95}{100})

\Rightarrow -1.5=(n-1)(-0.02)

\Rightarrow 1.5=(n-1)(0.02)

\Rightarrow n-1=\dfrac{1.5}{0.02}

\Rightarrow n-1=75

\Rightarrow n=76

Therefore, after 76 swings the angle through which it swings less than 1°

8 0
2 years ago
By visual inspection determine the best-fitting regression model for the data plot below
Pie

Answer:

Exponential

Step-by-step explanation:

By visual inspection the graph generated by the points plotted is an exponential graph as the graph curves upward. The graph is also continous and differs from either a decreasing or increasing Linear graph, which shows a straight best of fit pattern. Hence, the graph most closely represents an exponential graph from visual examination.

8 0
2 years ago
Read 2 more answers
Other questions:
  • Tristan records the number of customers who visit the store each hour on a Saturday. His data representing the first seven hours
    15·2 answers
  • The time at which the mailman delivers the mail to ace bike shop follows a normal distribution with mean 2:00 pm and standard de
    13·1 answer
  • An airplane is traveling at a speed of 200 miles/hour with a bearing of 240°. The wind velocity is 60 miles/hour at a bearing of
    10·1 answer
  • Which classification best describes the following system of equations? 3x+6y-12z=36 x=2y-4z=12 4x+8y-16z=48 inconsistent and dep
    5·1 answer
  • The price of a math book after a discount of 25% is $36. What is the original price of the math book?
    9·1 answer
  • A remote ranch has a cylindrical water storage tank. It has a vertical central axis, a diameter of 16 ft, the sides are 5 ft hig
    13·1 answer
  • (b) Ali uses 11% of his $2345 to buy a television.
    10·1 answer
  • Today is the Harperville Fall for Fun festival, and Naomi is volunteering at the balloon stand. When she practiced last night, N
    7·1 answer
  • Suppose you are producing an outdoor festival. You estimate that you will make $150000 if it does not rain and make $50000 if it
    8·1 answer
  • The angle of elevation to a nearby tree from a point on the ground is measured to be 47^{\circ} ∘ . How tall is the tree if the
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!