Find the area of the figure. If needed, round to the nearest tenth.

Mary wants to have$8500 to travel to south america when she is 21. She currently has $6439 in a savings account earning 4% annua

attashe74 [19]

Answer:

9,014.6

Step-by-step explanation:

4 0

3 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 $\rho sin\phi=1$

7 0

3 years ago

A taxi charges a pick-up fee p!us a charge per mile. Maria paid $15.00 for a 7 mile rode. To my paid $19.50 for a 10 mile ride.

lukranit [14]

Answer:

The y-intercept in coordinate form is (0, 4.5) and represents the taxi pick-up fee. The equation is y=1.5x + 4.5.

Step-by-step explanation:

This question is asking for the slope and y-intercept of a linear equation. A linear equation makes a straight line based on a constant rate of change. For this problem, the cost per mile is the slope, while the independent variable 'x' is the number of miles and the dependent variable 'y' is the total cost. In order to first find slope, you need to use the two points given (7, 15) and (10, 19.5) to set up a change in y / change in x, or (19.5-15)/(10-7) or 4.5/3 which is 1.5. So the slope, or cost per mile is $1.50. To find the y-intercept (b), or the cost of the pick-up fee, simply fill in your equation y=1.5x + b with your other variables and solve for 'b'. So, 15 = (1.5 x7) + b. or 15 = 10.5 +b, subtract 10.5 from both sides of the equation to get b=4.5.

5 0

4 years ago

Is the sum of any two numbers is greater than the larger of the two numbers?

rjkz [21]

Answer: Yes the sum of any two numbers is greater than the larger of the two numbers.

Step-by-step explanation:

Yes the sum of any two numbers is greater than the larger of the two numbers.

Let us assume that the two numbers are a and b and ab is the number.

a + b > a

b > a – a

b > 0

This therefore implies that b > 0.

This may however not be true when the value of b is zero(0) or a negative number.

5 0

4 years ago

Find the opposite of the polynomial.<br> -60^3 - 8a +5

GrogVix [38]

Answer:

60^3 + 8a -5

Step-by-step explanation:

Like opposite of 5 is 5×-1 = -5,

Opposite of -60³ - 8a +5 is:

-(-60³ - 8a +5)

60³ + 8a - 5

3 0

3 years ago

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