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3 years ago

Describe the effect on the area of a circle when the radius is doubled

Mathematics

1 answer:

galina1969 [7]3 years ago

5 0

Answer:

The original area would be multiplied by the scale factor of 2² to get the new area.

Step-by-step explanation:

If you double the radius lets so lets do an example

(a=πr²) so

if x is the radius the area would be x²π

double the radius so 2x then the area would be

(2x)²π so 4x²π

4x²π/x²π= 4 so its 4 times greater or

D the last answer or The original area would be multiplied by the scale factor of 2² to get the new area.

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VashaNatasha [74]

The ratio is supposed to be pennies to total amount of coins. The total amount of coins--including pennies--is 16. This can be proven by this equation:

5 + 6 + 5 = 16

Now you put the ratio together by taking the amount of pennies (5) and total amount of coins (16). Your ratio should look like this:

5:16

Hope I helped you out! ❤❤

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3 years ago

Me need help in math:(help fast

Kamila [148]

Answer:

9.5 feet

Step-by-step explanation:

15.5-6=9.5

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3 years ago

Your parents decide to build a rectangular pool in your backyard. They determine that the length of the pool should be 15 feet l

damaskus [11]

Width = X

Length = X + 15

Perimeter of a Rectangle = 2W + 2L

2(X) + 2(X + 15)

2X + 2X + 30

4X + 30

Answer = 4X + 30

Hope this helps! :)

4 0

3 years ago

Solve dis attachment and show all work ( I got it all wrong and I want to know how to solve it )

DedPeter [7]

(a) First find the intersections of $y=e^{2x-x^2}$ and $y=2$ :

$2=e^{2x-x^2}\implies \ln2=2x-x^2\implies x=1\pm\sqrt{1-\ln2}$

So the area of $R$ is given by

$\displaystyle\int_{1-\sqrt{1-\ln2}}^{1+\sqrt{1-\ln2}}\left(e^{2x-x^2}-2\right)\,\mathrm dx$

If you're not familiar with the error function $\mathrm{erf}(x)$ , then you will not be able to find an exact answer. Fortunately, I see this is a question on a calculator based exam, so you can use whatever built-in function you have on your calculator to evaluate the integral. You should get something around 0.5141.

(b) Find the intersections of the line $y=1$ with $y=e^{2x-x^2}$ .

$1=e^{2x-x^2}\implies 0=2x-x^2\implies x=0,x=2$

So the area of $S$ is given by

$\displaystyle\int_0^{1-\sqrt{1-\ln2}}\left(e^{2x-x^2}-1\right)\,\mathrm dx+\int_{1-\sqrt{1-\ln2}}^{1+\sqrt{1-\ln2}}(2-1)\,\mathrm dx+\int_{1+\sqrt{1-\ln2}}^2\left(e^{2x-x^2}-1\right)\,\mathrm dx$
$\displaystyle=2\int_0^{1-\sqrt{1-\ln2}}\left(e^{2x-x^2}-1\right)\,\mathrm dx+\int_{1-\sqrt{1-\ln2}}^{1+\sqrt{1-\ln2}}\mathrm dx$

which is approximately 1.546.

(c) The easiest method for finding the volume of the solid of revolution is via the disk method. Each cross-section of the solid is a circle with radius perpendicular to the x-axis, determined by the vertical distance from the curve $y=e^{2x-x^2}$ and the line $y=1$ , or $e^{2x-x^2}-1$ . The area of any such circle is $\pi$ times the square of its radius. Since the curve intersects the axis of revolution at $x=0$ and $x=2$ , the volume would be given by

$\displaystyle\pi\int_0^2\left(e^{2x-x^2}-1\right)^2\,\mathrm dx$

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3 years ago

A jacket is priced at $90.00 but has a discount of 40%. what is the sale price?<br> show work!

alexdok [17]

Answer:

$36

Step-by-step explanation:

90*0.40=36

40%=0.40

8 0

4 years ago

Read 2 more answers