In circle D, which is a secant? <br> A. EF<br> B. DC<br> C. AB<br> D. GH

Find the surface area of x^2+y^2+z^2=9 that lies above the cone z= sqrt(x^@+y^2)

Mashcka [7]

The cone equation gives

$z=\sqrt{x^2+y^2}\implies z^2=x^2+y^2$

which means that the intersection of the cone and sphere occurs at

$x^2+y^2+(x^2+y^2)=9\implies x^2+y^2=\dfrac92$

i.e. along the vertical cylinder of radius $\dfrac3{\sqrt2}$ when $z=\dfrac3{\sqrt2}$ .

We can parameterize the spherical cap in spherical coordinates by

$\mathbf r(\theta,\varphi)=\langle3\cos\theta\sin\varphi,3\sin\theta\sin\varphi,3\cos\varphi\right\rangle$

where $0\le\theta\le2\pi$ and $0\le\varphi\le\dfrac\pi4$ , which follows from the fact that the radius of the sphere is 3 and the height at which the sphere and cone intersect is $\dfrac3{\sqrt2}$ . So the angle between the vertical line through the origin and any line through the origin normal to the sphere along the cone's surface is

$\varphi=\cos^{-1}\left(\dfrac{\frac3{\sqrt2}}3\right)=\cos^{-1}\left(\dfrac1{\sqrt2}\right)=\dfrac\pi4$

Now the surface area of the cap is given by the surface integral,

$\displaystyle\iint_{\text{cap}}\mathrm dS=\int_{\theta=0}^{\theta=2\pi}\int_{\varphi=0}^{\varphi=\pi/4}\|\mathbf r_u\times\mathbf r_v\|\,\mathrm dv\,\mathrm du$
$=\displaystyle\int_{u=0}^{u=2\pi}\int_{\varphi=0}^{\varphi=\pi/4}9\sin v\,\mathrm dv\,\mathrm du$
$=-18\pi\cos v\bigg|_{v=0}^{v=\pi/4}$
$=18\pi\left(1-\dfrac1{\sqrt2}\right)$
$=9(2-\sqrt2)\pi$

3 0

2 years ago

Which expression shows that 11 + 7 = 5 + 13?

Naily [24]

The addition method.

4 0

3 years ago

Function f is differentiable and decreasing for all real numbers. If y=f(2x^3 - 3x^2), for which of the following intervals of x

vichka [17]

Answer:

The terai region extends from the chure range in the north to the border of India in the south.lt covers 17 percent of total land of Nepal .this terai region is mostly flat and plain with alluvial fertile deposited by the rivers . the climate of the reason is hot and wet in summer and cold and dry in winter.Terai also called the granary of Nepal as more than half percent of people of Nepal depend on the vegetation of Terai region. Terai is plain, where more cultivation is possible. Cultivation is impossible in mountain region due to difficult topography and temperate region and even in hilly region with lots of vegetation it's not possible due to slope area. Terai is only the possible region where much cultivation is possible. Different kinds of vegetation, valuable medicinal herbs, important trees, etc. are found in Terai region. So, Terai region is called the granary of Nepal.The terai region extends from the chure range in the north to the border of India in the south.lt covers 17 percent of total land of Nepal .this terai region is mostly flat and plain with alluvial fertile deposited by the rivers . the climate of the reason is hot and wet in summer and cold and dry in winter.Terai also called the granary of Nepal as more than half percent of people of Nepal depend on the vegetation of Terai region. Terai is plain, where more cultivation is possible. Cultivation is impossible in mountain region due to difficult topography and temperate region and even in hilly region with lots of vegetation it's not possible due to slope area. Terai is only the possible region where much cultivation is possible. Different kinds of vegetation, valuable medicinal herbs, important trees, etc. are found in Terai region. So, Terai region is called the granary of Nepal.The terai region extends from the chure range in the north to the border of India in the south.lt covers 17 percent of total land of Nepal .this terai region is mostly flat and plain with alluvial fertile deposited by the rivers . the climate of the reason is hot and wet in summer and cold and dry in winter.Terai also called the granary of Nepal as more than half percent of people of Nepal depend on the vegetation of Terai region. Terai is plain, where more cultivation is possible. Cultivation is impossible in mountain region due to difficult topography and temperate region and even in hilly region with lots of vegetation it's not possible due to slope area. Terai is only the possible region where much cultivation is possible. Different kinds of vegetation, valuable medicinal herbs, important trees, etc. are found in Terai region. So, Terai region is called the granary of Nepal.

4 0

2 years ago

Maria needs 22 cups of milk to make banana milk shakes for her friends. If 1 pint is equal to 2 cups, how many pints of milk sho

kodGreya [7K]

22×2 =44 is the answer

3 0

3 years ago

Read 2 more answers

Angles 1 and 2 are complementary. If angle 1 = 35, then what is the measure of angle 2?

enot [183]

Answer:

doge

Step-by-step explanation:

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4 0

2 years ago

In circle D, which is a secant? A. EF B. DC C. AB D. GH