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3 years ago

Please helpppp Extra points and brainleist

Mathematics

1 answer:

vladimir1956 [14]3 years ago

5 0

Answer:

Step-by-step explanation:

x² - 4x - 7 = 0

(x - 2)² = 11

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The cone in the diagram below has a radius of 10 mm and its height is 24 mm.

Amiraneli [1.4K]

Slant height l is 26 mm

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2 years ago

Read 2 more answers

Bus A and Bus B leave the the bus depot at 2 pm.

Tanya [424]

Answer:

3:15 pm

Step-by-step explanation:

You can imagine that they go in a circle (we can do whatever we want in theoretical math and physics). By doing so we know we can obtain a cosinusoidal wave by projecting the motion on a plane. Each one of the buses has a period (minimum time after what they're in the same point again). For the first one it's 15 minutes, for the second one it's 20 minutes. We have to take the least common multiple of the periods, that is 75 minutes. So They'll meet every 75 minutes. Add 75 minutes (1h and 15 minutes) to 2pm and there you go.

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2 years ago

Simplify the expression:<br><br> m - 1/6 - 4m + 5/6

Oduvanchick [21]

Answer:

-3m+2/3. 2/3 is a fraction

Step-by-step explanation:

8 0

3 years ago

A torus is formed by rotating a circle of radius r about a line in the plane of the circle that is a distance R (> r) from th

jeyben [28]

Consider a circle with radius $r$ centered at some point $(R+r,0)$ on the $x$ -axis. This circle has equation

$(x-(R+r))^2+y^2=r^2$

Revolve the region bounded by this circle across the $y$ -axis to get a torus. Using the shell method, the volume of the resulting torus is

$\displaystyle2\pi\int_R^{R+2r}2xy\,\mathrm dx$

where $2y=\sqrt{r^2-(x-(R+r))^2}-(-\sqrt{r^2-(x-(R+r))^2})=2\sqrt{r^2-(x-(R+r))^2}$ .

So the volume is

$\displaystyle4\pi\int_R^{R+2r}x\sqrt{r^2-(x-(R+r))^2}\,\mathrm dx$

Substitute

$x-(R+r)=r\sin t\implies\mathrm dx=r\cos t\,\mathrm dt$

and the integral becomes

$\displaystyle4\pi r^2\int_{-\pi/2}^{\pi/2}(R+r+r\sin t)\cos^2t\,\mathrm dt$

Notice that $\sin t\cos^2t$ is an odd function, so the integral over $\left[-\frac\pi2,\frac\pi2\right]$ is 0. This leaves us with

$\displaystyle4\pi r^2(R+r)\int_{-\pi/2}^{\pi/2}\cos^2t\,\mathrm dt$

Write

$\cos^2t=\dfrac{1+\cos(2t)}2$

so the volume is

$\displaystyle2\pi r^2(R+r)\int_{-\pi/2}^{\pi/2}(1+\cos(2t))\,\mathrm dt=\boxed{2\pi^2r^2(R+r)}$

6 0

3 years ago

The length of a rectangular frame is 5 cm more than the width. The area inside the frame is 66 square cm. Find the width of the

Ratling [72]

For this case we have that the area is given by:
A = (w) * (l)
Where,
w: width
l: long
Substituting we have:
66 = (w) * (w + 5)
Rewriting
w ^ 2 + 5w - 66 = 0
(w + 11) * (w-6) = 0
Using the positive root we have:
w = 6
Answer:
the width of the frame is:
w = 6 cm

6 0

3 years ago