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3 years ago

Find the total surface area in square inches, of the following 3-

Mathematics

1 answer:

Ivenika [448]3 years ago

6 0

Answer:

81 in²

Step-by-step explanation:

The 3-dimensional shape given is a square pyramid having a square base, and 4 right triangular side faces that are the same.

The surface area can be calculated by finding the area of the square base and the area of the 4 triangular side faces. Then sum all the areas together.

Or, we can use the following formula below: Base Area + ½(Perimeter of base) × Slant Length

Where,

Base area = s² = 5² = 25 in²

Perimeter of base = 4(s) = 4(5) = 20 in

Slant height = 5.6 in

Surface area = 25 + ½(20) × 5.6

= 25 + 10 × 5.6

= 25 + 56

Surface area = 81 in²

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1<br> Solve - (8x – 12) = 2x – 3<br> 4<br> 218x -<br> pleaseee help!!

Alex Ar [27]

Answer:

1/4.(-96)=2x-3

-1/4.96=2x-3

-24=2x-3

-2x-24=-3

-2x=-3+24

-2x=21

x=-21/2

Step-by-step explanation:

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2 years ago

Name/ Uid:1. In this problem, try to write the equations of the given surface in the specified coordinates.(a) Write an equation

Gemiola [76]

To find:

(a) Equation for the sphere of radius 5 centered at the origin in cylindrical coordinates

(b) Equation for a cylinder of radius 1 centered at the origin and running parallel to the z-axis in spherical coordinates

Solution:

(a) The equation of a sphere with center at (a, b, c) & having a radius 'p' is given in cartesian coordinates as:

$(x-a)^{2}+(y-b)^{2}+(z-c)^{2}=p^{2}$

Here, it is given that the center of the sphere is at origin, i.e., at (0,0,0) & radius of the sphere is 5. That is, here we have,

$a=b=c=0,p=5$

That is, the equation of the sphere in cartesian coordinates is,

$(x-0)^{2}+(y-0)^{2}+(z-0)^{2}=5^{2}$

$\Rightarrow x^{2}+y^{2}+z^{2}=25$

Now, the cylindrical coordinate system is represented by $(r, \theta,z)$

The relation between cartesian and cylindrical coordinates is given by,

$x=rcos\theta,y=rsin\theta,z=z$

$r^{2}=x^{2}+y^{2},tan\theta=\frac{y}{x},z=z$

Thus, the obtained equation of the sphere in cartesian coordinates can be rewritten in cylindrical coordinates as,

$r^{2}+z^{2}=25$

This is the required equation of the given sphere in cylindrical coordinates.

(b) A cylinder is defined by the circle that gives the top and bottom faces or alternatively, the cross section, & it's axis. A cylinder running parallel to the z-axis has an axis that is parallel to the z-axis. The equation of such a cylinder is given by the equation of the circle of cross-section with the assumption that a point in 3 dimension lying on the cylinder has 'x' & 'y' values satisfying the equation of the circle & that 'z' can be any value.

That is, in cartesian coordinates, the equation of a cylinder running parallel to the z-axis having radius 'p' with center at (a, b) is given by,

$(x-a)^{2}+(y-b)^{2}=p^{2}$

Here, it is given that the center is at origin & radius is 1. That is, here, we have, $a=b=0,p=1$ . Then the equation of the cylinder in cartesian coordinates is,

$x^{2}+y^{2}=1$

Now, the spherical coordinate system is represented by $(\rho,\theta,\phi)$

The relation between cartesian and spherical coordinates is given by,

$x=\rho sin\phi cos\theta,y=\rho sin\phi sin\theta, z= \rho cos\phi$

Thus, the equation of the cylinder can be rewritten in spherical coordinates as,

$(\rho sin\phi cos\theta)^{2}+(\rho sin\phi sin\theta)^{2}=1$

$\Rightarrow \rho^{2} sin^{2}\phi cos^{2}\theta+\rho^{2} sin^{2}\phi sin^{2}\theta=1$

$\Rightarrow \rho^{2} sin^{2}\phi (cos^{2}\theta+sin^{2}\theta)=1$

$\Rightarrow \rho^{2} sin^{2}\phi=1$ (As $sin^{2}\theta+cos^{2}\theta=1$ )

Note that $\rho$ represents the distance of a point from the origin, which is always positive. $\phi$ represents the angle made by the line segment joining the point with z-axis. The range of $\phi$ is given as $0\leq \phi\leq \pi$ . We know that in this range the sine function is positive. Thus, we can say that $sin\phi$ is always positive.

Thus, we can square root both sides and only consider the positive root as,

$\Rightarrow \rho sin\phi=1$

This is the required equation of the cylinder in spherical coordinates.

Final answer:

(a) The equation of the given sphere in cylindrical coordinates is $r^{2}+z^{2}=25$

(b) The equation of the given cylinder in spherical coordinates is $\rho sin\phi=1$

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3 years ago

Find the vertex and focus of the<br> parabola.<br> y2 – 4y + 12x – 8 = 0

IceJOKER [234]

Answer:

1,2

-2 2

Step-by-step explanation:

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2 years ago

If 62% of customers prefer low cholesterol bacon, what number of degrees on a pie chart would be used to represent this?

Natalija [7]

62% of 360° = 0.62*360° = 223.2°

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2 years ago

Hamza is graphing the parabola represented by this equation. 3x-6y^2+6y=0<br> The answer is below!!!

aivan3 [116]

Hamza should draw the vertex at (-0.5, 0.5), the directrix at -0.625, and the focus at (-0.375, 0.5). The parabola will open to the right

The given equation is 3x-6y²+6y=0.

<h3>What is the parabola?</h3>

An equation of a curve that has a point on it that is equally spaced from a fixed point and a fixed line is referred to as a parabola. The parabola's fixed line and fixed point are together referred to as the directrix and focus, respectively.

Graph the parabola using the direction, vertex, focus, and axis of symmetry.

Direction: Opens Right

Vertex: (-1/2, 1/2)

Focus: (-3/8, 1/2)

Axis of symmetry: y=1/2

Directrix: x=-5/8

The coordinate points to plot (-1/2, 1/2), (0.5, 1.21), (0.5, -1.21), (1.5, 1.5) and (1.5, -0.5).

Therefore, Hamza should draw the vertex at (-0.5, 0.5), the directrix at -0.625, and the focus at (-0.375, 0.5). The parabola will open to the right.

To learn more about the parabola visit:

brainly.com/question/21685473.

#SPJ1

4 0

1 year ago