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3 years ago

The diameter of circle p below is 39.4 what is the approximate area of circle p???

Mathematics

1 answer:

givi [52]3 years ago

7 0

1134.11

This should be the answer

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I’m really stuck<br> Can. Someone help?

const2013 [10]

Answer:

$-2\leq x < 8$

Step-by-step explanation:

Notice that the leftmost endpoint, 2, has a closed circle, which means that it is included in the inequality. Also, the rightmost endpoint, 8, has an open circle, which means that is NOT included in the inequality.

Because the inequality only includes what is between the two numbers, you write the inequality as $-2\leq x < 8$ to show that -2 is included and 8 is not included.

8 0

2 years ago

For each vector field f⃗ (x,y,z), compute the curl of f⃗ and, if possible, find a function f(x,y,z) so that f⃗ =∇f. if no such f

butalik [34]

$\vec f(x,y,z)=(2yze^{2xyz}+4z^2\cos(xz^2))\,\vec\imath+2xze^{2xyz}\,\vec\jmath+(2xye^{2xyz}+8xz\cos(xz^2))\,\vec k$

Let

$\vec f=f_1\,\vec\imath+f_2\,\vec\jmath+f_3\,\vec k$

The curl is

$\nabla\cdot\vec f=(\partial_x\,\vec\imath+\partial_y\,\vec\jmath+\partial_z\,\vec k)\times(f_1\,\vec\imath+f_2\,\vec\jmath+f_3\,\vec k)$

where $\partial_\xi$ denotes the partial derivative operator with respect to $\xi$ . Recall that

$\vec\imath\times\vec\jmath=\vec k$

$\vec\jmath\times\vec k=\vec i$

$\vec k\times\vec\imath=\vec\jmath$

and that for any two vectors $\vec a$ and $\vec b$ , $\vec a\times\vec b=-\vec b\times\vec a$ , and $\vec a\times\vec a=\vec0$ .

The cross product reduces to

$\nabla\times\vec f=(\partial_yf_3-\partial_zf_2)\,\vec\imath+(\partial_xf_3-\partial_zf_1)\,\vec\jmath+(\partial_xf_2-\partial_yf_1)\,\vec k$

When you compute the partial derivatives, you'll find that all the components reduce to 0 and

$\nabla\times\vec f=\vec0$

which means $\vec f$ is indeed conservative and we can find $f$ .

Integrate both sides of

$\dfrac{\partial f}{\partial y}=2xze^{2xyz}$

with respect to $y$ and

$\implies f(x,y,z)=e^{2xyz}+g(x,z)$

Differentiate both sides with respect to $x$ and

$\dfrac{\partial f}{\partial x}=\dfrac{\partial(e^{2xyz})}{\partial x}+\dfrac{\partial g}{\partial x}$

$2yze^{2xyz}+4z^2\cos(xz^2)=2yze^{2xyz}+\dfrac{\partial g}{\partial x}$

$4z^2\cos(xz^2)=\dfrac{\partial g}{\partial x}$

$\implies g(x,z)=4\sin(xz^2)+h(z)$

Now

$f(x,y,z)=e^{2xyz}+4\sin(xz^2)+h(z)$

and differentiating with respect to $z$ gives

$\dfrac{\partial f}{\partial z}=\dfrac{\partial(e^{2xyz}+4\sin(xz^2))}{\partial z}+\dfrac{\mathrm dh}{\mathrm dz}$

$2xye^{2xyz}+8xz\cos(xz^2)=2xye^{2xyz}+8xz\cos(xz^2)+\dfrac{\mathrm dh}{\mathrm dz}$

$\dfrac{\mathrm dh}{\mathrm dz}=0$

$\implies h(z)=C$

for some constant $C$ . So

$f(x,y,z)=e^{2xyz}+4\sin(xz^2)+C$

3 0

4 years ago

Alim buys 2 t-shirts for $9.50 each, a 3-pack of socks for $7.95, and a pair of shoes for $7.95 and a pair of shoes for $49.95.

Usimov [2.4K]

First, I add all of my prices together.
$9.50(2)+$7.95+$7.95+$49.95= $84.85
Change 6% to a decimal = .06
Then multiply: 84.85 x .06 = $5.09
$5.09 is the sales tax
$84.85 + $5.09 = $89.94

Answer: $89.94
I hope this helps :)

3 0

4 years ago

How do you find the surface area of a octahedron

Alenkasestr [34]

If it's a regular octahedron, then you can calculate it using the formula $2\sqrt3a^2$ where $a$ is the length of the edge.
If it's not regular, you have to calculate the area of each side individually.

6 0

3 years ago

How to simplify 4r + 4s + 3r + 3s + 5p

ratelena [41]

Answer: 7r + 7s + 5p

Step-by-step explanation: mr. shrek, im a big fan *debbie ryan smailes*

(^///^)

8 0

3 years ago

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