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3 years ago

I need help is -7+9 = -9+7 true false or open

Mathematics

1 answer:

victus00 [196]3 years ago

3 0

Answer:

false

Step-by-step explanation:

-7+9 = 2

-9+7 = -2

2 does not equal -2

False

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G find the area of the surface over the given region. use a computer algebra system to verify your results. the sphere r(u,v) =

Svetach [21]

Presumably you should be doing this using calculus methods, namely computing the surface integral along $\mathbf r(u,v)$ .

But since $\mathbf r(u,v)$ describes a sphere, we can simply recall that the surface area of a sphere of radius $a$ is $4\pi a^2$ .

In calculus terms, we would first find an expression for the surface element, which is given by

$\displaystyle\iint_S\mathrm dS=\iint_S\left\|\frac{\partial\mathbf r}{\partial u}\times\frac{\partial\mathbf r}{\partial v}\right\|\,\mathrm du\,\mathrm dv$

$\dfrac{\partial\mathbf r}{\partial u}=a\cos u\cos v\,\mathbf i+a\cos u\sin v\,\mathbf j-a\sin u\,\mathbf k$
$\dfrac{\partial\mathbf r}{\partial v}=-a\sin u\sin v\,\mathbf i+a\sin u\cos v\,\mathbf j$
$\implies\dfrac{\partial\mathbf r}{\partial u}\times\dfrac{\partial\mathbf r}{\partial v}=a^2\sin^2u\cos v\,\mathbf i+a^2\sin^2u\sin v\,\mathbf j+a^2\sin u\cos u\,\mathbf k$
$\implies\left\|\dfrac{\partial\mathbf r}{\partial u}\times\dfrac{\partial\mathbf r}{\partial v}\right\|=a^2\sin u$

So the area of the surface is

$\displaystyle\iint_S\mathrm dS=\int_{u=0}^{u=\pi}\int_{v=0}^{v=2\pi}a^2\sin u\,\mathrm dv\,\mathrm du=2\pi a^2\int_{u=0}^{u=\pi}\sin u$
$=-2\pi a^2(\cos\pi-\cos 0)$
$=-2\pi a^2(-1-1)$
$=4\pi a^2$

as expected.

6 0

3 years ago

Which coordinate plane shows the graph of the function y = ?

Brilliant_brown [7]

Y=1/2 x so graph B i think.

5 0

3 years ago

Read 2 more answers

Solve <br><br> 9x-14-2x=5(2x-6)

deff fn [24]

$9x-14-2x=5(2x-6)\qquad\text{use distributive property}\\\\(9x-2x)-14=(5)(2x)+(5)(-6)\\\\7x-14=10x-30\qquad\text{add 14 to both sides}\\\\7x=10x-16\qquad\text{subtract 10x from both sides}\\\\-3x=-16\qquad\text{divide both sides by (-3)}\\\\\boxed{x=\dfrac{16}{3}}$

8 0

3 years ago

Solve.<br> 9x + 6y = -3<br> y = -8

klio [65]

Answer:

Step-by-step explanation:

9x+6y=-3

9x+6(-8)=-3

9x-48=-3

9x=45

x=5

6 0

3 years ago

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Classify the following triangle

jek_recluse [69]

Acute-The angle is less than 90 degrees

Equilateral-All sides are equal in length

Isosceles-Two of the sides are equal in length

Scalene-None of the sides are equal in length

Right-The angle is 90 degrees

Obtuse-The angle is greater than 90 degrees

We can see that none of the sides are the same length, so we know that it must be scalene. We can also see that every angle is less than 90 degrees, so we know that is must be acute.

The triangle is scalene and acute.

Hope this helps!!

3 0

3 years ago