6 square root -16 + 4 square root -49

A cone has a diameter of 30 in. and a slant height of 17 in. What is the approximate volume of the cone?

Alex777 [14]

We need to find the height of the cylinder
pythagorean theorem
15 is the bottom leg (30/2=15)
17 is hypotonuse
b=height
15^2+b^2=17^2
225+b^2=289
minus 225 both sides
b^2=64
sqrt both sides b=8

Vcone=(1/3)hpir^2
d/2=r=30/2=15
h=8
V=(1/3)8pi15^2
V=(1/3)8pi225
V=8pi75
V=600pi
aprox pi=3.14159256
V=1884.955536 in^3
round if nececary

7 0

3 years ago

For <img src="https://tex.z-dn.net/?f=e%5E%7B-x%5E2%2F2%7D" id="TexFormula1" title="e^{-x^2/2}" alt="e^{-x^2/2}" align="absmiddl

nevsk [136]

I'm assuming you're talking about the indefinite integral

$\displaystyle\int e^{-x^2/2}\,\mathrm dx$

and that your question is whether the substitution $u=\dfrac x{\sqrt2}$ would work. Well, let's check it out:

$u=\dfrac x{\sqrt2}\implies\mathrm du=\dfrac{\mathrm dx}{\sqrt2}$
$\implies\displaystyle\int e^{-x^2/2}\,\mathrm dx=\sqrt2\int e^{-(\sqrt2\,u)^2/2}\,\mathrm du$
$=\displaystyle\sqrt2\int e^{-u^2}\,\mathrm du$

which essentially brings us to back to where we started. (The substitution only served to remove the scale factor in the exponent.)

What if we tried $u=\sqrt t$ next? Then $\mathrm du=\dfrac{\mathrm dt}{2\sqrt t}$ , giving

$=\displaystyle\frac1{\sqrt2}\int \frac{e^{-(\sqrt t)^2}}{\sqrt t}\,\mathrm dt=\frac1{\sqrt2}\int\frac{e^{-t}}{\sqrt t}\,\mathrm dt$

Next you may be tempted to try to integrate this by parts, but that will get you nowhere.

So how to deal with this integral? The answer lies in what's called the "error function" defined as

$\mathrm{erf}(x)=\displaystyle\frac2{\sqrt\pi}\int_0^xe^{-t^2}\,\mathrm dt$

By the fundamental theorem of calculus, taking the derivative of both sides yields

$\dfrac{\mathrm d}{\mathrm dx}\mathrm{erf}(x)=\dfrac2{\sqrt\pi}e^{-x^2}$

and so the antiderivative would be

$\displaystyle\int e^{-x^2/2}\,\mathrm dx=\sqrt{\frac\pi2}\mathrm{erf}\left(\frac x{\sqrt2}\right)$

The takeaway here is that a new function (i.e. not some combination of simpler functions like regular exponential, logarithmic, periodic, or polynomial functions) is needed to capture the antiderivative.

3 0

2 years ago

How high did Abby climb above their original starting<br> position?

PIT_PIT [208]

Idk what are the possible answers

7 0

2 years ago

Read 2 more answers

Write an equation of the line that passes through the given point P and has the given slope m.

Tpy6a [65]

9514 1404 393

Answer:

y -4 = -1/3(x -9)

Step-by-step explanation:

The point-slope form of the equation for a line is useful for this.

y -k = m(x -h) . . . . . . . line through point (h, k) with slope m

You are given (h, k) = (9, 4) and m = -1/3. Putting these values into the form gives the equation ...

y -4 = -1/3(x -9)

8 0

3 years ago

A police officer seals off the scene of an accident using a roll of yellow tape that is 272 feet long. What dimensions should be

klasskru [66]

Answer:

68 feet square

Step-by-step explanation:

The rectangle with the maximum area for a given perimeter is a square. The perimeter of a square is 4 times the side length, so the side length of the square area will be ...

(272 ft)/4 = 68 ft

_____

<em>More formally ...</em>

You can let x represent the length of one side. Then the length of the other side for the given perimeter will be 136 -x, and the area will be the product ...

area = x(136 -x)

The area function is a quadratic with zeros at x=0 and x=136. The vertex (maximum area) will be at the value of x that is on the line of symmetry between these points, at their midpoint: x = (0 +136)/2 = 68. This value of x makes the rectangle a square.

5 0

3 years ago