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3 years ago

Describe when to use a series and when to use an equation.

Mathematics

1 answer:

Genrish500 [490]3 years ago

3 0

Answer:

A series is used only for n taking the values of natural numbers

But a function or an equation is used for all real values of x. It is not necessary that x should be a natural number.

Step-by-step explanation:

The equation is used when domain is all real values

f(x) = 3x+5 is valid for all x real. x can take values as irrational also, negative or fractions.

But in a series, such as 2+3n, we have the restriction for domain n as only the set of all natural numbers

Here n cannot take negative or 0 or fractions or irrational numbers.

Thus the domain is the one which makes the difference of using an equation and a series.

A series is used only for n taking the values of natural numbers

But a function or an equation is used for all real values of x. It is not necessary that x should be a natural number.

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Section a of a theater contains 12 rows of 15 seats each section b contains only 10 rows but had the same number of seats as sec

yuradex [85]

Answer:

15 seats

Step-by-step explanation:

It is given that section A of a theater contains 12 rows of 15 seats each.

Now, it is also given that section B contains only 10 rows it has an equal number of seats the same as section A.

As the number of seats in each row of section A is 15, so, the number of seats in each row of section B will be 15 and the same as section A. (Answer)

8 0

3 years ago

Which equation has exactly one solution in common with the equation y=6x-2?

GalinKa [24]

Answer:

A. 18x - 3y = 6

Step-by-step explanation:

By taking 3 common from the terms 18x and 3y we get,

3 (6x-3y) = 6

or, 6x - y = 6/3

or, 6x - y = 2

And,

The equation becomes,

y = 6x - 2

5 0

3 years ago

Problem 4: Let F = (2z + 2)k be the flow field. Answer the following to verify the divergence theorem: a) Use definition to find

Viktor [21]

Given that you mention the divergence theorem, and that part (b) is asking you to find the downward flux through the disk $x^2+y^2\le3$ , I think it's same to assume that the hemisphere referred to in part (a) is the upper half of the sphere $x^2+y^2+z^2=3$ .

a. Let $C$ denote the hemispherical <u>c</u>ap $z=\sqrt{3-x^2-y^2}$ , parameterized by

$\vec r(u,v)=\sqrt3\cos u\sin v\,\vec\imath+\sqrt3\sin u\sin v\,\vec\jmath+\sqrt3\cos v\,\vec k$

with $0\le u\le2\pi$ and $0\le v\le\frac\pi2$ . Take the normal vector to $C$ to be

$\vec r_v\times\vec r_u=3\cos u\sin^2v\,\vec\imath+3\sin u\sin^2v\,\vec\jmath+3\sin v\cos v\,\vec k$

Then the upward flux of $\vec F=(2z+2)\,\vec k$ through $C$ is

$\displaystyle\iint_C\vec F\cdot\mathrm d\vec S=\int_0^{2\pi}\int_0^{\pi/2}((2\sqrt3\cos v+2)\,\vec k)\cdot(\vec r_v\times\vec r_u)\,\mathrm dv\,\mathrm du$

$\displaystyle=3\int_0^{2\pi}\int_0^{\pi/2}\sin2v(\sqrt3\cos v+1)\,\mathrm dv\,\mathrm du$

$=\boxed{2(3+2\sqrt3)\pi}$

b. Let $D$ be the disk that closes off the hemisphere $C$ , parameterized by

$\vec s(u,v)=u\cos v\,\vec\imath+u\sin v\,\vec\jmath$

with $0\le u\le\sqrt3$ and $0\le v\le2\pi$ . Take the normal to $D$ to be

$\vec s_v\times\vec s_u=-u\,\vec k$

Then the downward flux of $\vec F$ through $D$ is

$\displaystyle\int_0^{2\pi}\int_0^{\sqrt3}(2\,\vec k)\cdot(\vec s_v\times\vec s_u)\,\mathrm du\,\mathrm dv=-2\int_0^{2\pi}\int_0^{\sqrt3}u\,\mathrm du\,\mathrm dv$

$=\boxed{-6\pi}$

c. The net flux is then $\boxed{4\sqrt3\pi}$ .

d. By the divergence theorem, the flux of $\vec F$ across the closed hemisphere $H$ with boundary $C\cup D$ is equal to the integral of $\mathrm{div}\vec F$ over its interior:

$\displaystyle\iint_{C\cup D}\vec F\cdot\mathrm d\vec S=\iiint_H\mathrm{div}\vec F\,\mathrm dV$

We have

$\mathrm{div}\vec F=\dfrac{\partial(2z+2)}{\partial z}=2$

so the volume integral is

$2\displaystyle\iiint_H\mathrm dV$

which is 2 times the volume of the hemisphere $H$ , so that the net flux is $\boxed{4\sqrt3\pi}$ . Just to confirm, we could compute the integral in spherical coordinates:

$\displaystyle2\int_0^{\pi/2}\int_0^{2\pi}\int_0^{\sqrt3}\rho^2\sin\varphi\,\mathrm d\rho\,\mathrm d\theta\,\mathrm d\varphi=4\sqrt3\pi$

4 0

3 years ago

A wire with a length of 100 cm is cut into three parts. The length of wire of the first and second parts are the same. The lengt

dsp73

The first two pieces are the same, let each of those equal x, so you have x + x = 2x

The 3rd piece is the sum of the first two + 4, so this would be 2x + 4

Now you have 2x + 2x + 4 = 100 cm

Combine like terms:

4x +4 = 100

Subtract 4 from both sides

4x = 96

Divide both sides by 4

X = 24

First piece is 24 cm

Second piece is 24 cm

Third piece is 52 cm

8 0

2 years ago

Is it necessary to have a common denominator when you multiply two fractions? Explain.

Softa [21]

It is not necessary to have a common denominator when you multiply two fractions

<h3>How to determine the true statement?</h3>

The statement is about the relationship between the denominator of fractions when they are multiplied

Take for instance, we have the following fractions

a/b and x/y

In the above fractions, we have

Numerator = a and x

Denominator = b and y

Where b and y do not have the same value

When they are multiplied, we have

Product = ax/by

The denominators do not have the same value

And we were able to calculate the product

This means that the fraction denominator do not have to be common