Which Fraction is equal to -2/3 A. 2/-3 B. -3/2 C. -2/-3 D. 2/3

Hello people ~

Luden [163]

Cone details:

height: h cm

radius: r cm

Sphere details:

radius: 10 cm

================

From the endpoints (EO, UO) of the circle to the center of the circle (O), the radius is will be always the same.

Using Pythagoras Theorem

(a)

TO² + TU² = OU²

(h-10)² + r² = 10² [insert values]

r² = 10² - (h-10)² [change sides]

r² = 100 - (h² -20h + 100) [expand]

r² = 100 - h² + 20h -100 [simplify]

r² = 20h - h² [shown]

r = √20h - h² ["r" in terms of "h"]

(b)

volume of cone = 1/3 * π * r² * h

===========================

$\longrightarrow \sf V = \dfrac{1}{3} * \pi * (\sqrt{20h - h^2})^2 \ ( h)$

$\longrightarrow \sf V = \dfrac{1}{3} * \pi * (20h - h^2) (h)$

$\longrightarrow \sf V = \dfrac{1}{3} * \pi * (20 - h) (h) ( h)$

$\longrightarrow \sf V = \dfrac{1}{3} \pi h^2(20-h)$

To find maximum/minimum, we have to find first derivative.

(c)

First derivative

$\Longrightarrow \sf V' =\dfrac{d}{dx} ( \dfrac{1}{3} \pi h^2(20-h) )$

apply chain rule

$\sf \Longrightarrow V'=\dfrac{\pi \left(40h-3h^2\right)}{3}$

Equate the first derivative to zero, that is V'(x) = 0

$\Longrightarrow \sf \dfrac{\pi \left(40h-3h^2\right)}{3}=0$

$\Longrightarrow \sf 40h-3h^2=0$

$\Longrightarrow \sf h(40-3h)=0$

$\Longrightarrow \sf h=0, \ 40-3h=0$

$\Longrightarrow \sf h=0,\:h=\dfrac{40}{3}$

maximum volume: when h = 40/3

$\sf \Longrightarrow max= \dfrac{1}{3} \pi (\dfrac{40}{3} )^2(20-\dfrac{40}{3} )$

$\sf \Longrightarrow maximum= 1241.123 \ cm^3$

minimum volume: when h = 0

$\sf \Longrightarrow min= \dfrac{1}{3} \pi (0)^2(20-0)$

$\sf \Longrightarrow minimum=0 \ cm^3$

6 0

2 years ago

Read 2 more answers

The drama club is having a car wash as a fundraiser. They wash x cars at $5 each

Galina-37 [17]

Answer:

x + y ≥ 26 + 15

5x + 8y ≥ 250 (see below)

Step-by-step explanation:

First, write an equation to represent the total cost to wash cars:

$5x = cost for cars

Then, write another for trucks:

$8y = cost for trucks

If the question is saying that they will wash at least 26 cars and 15 trucks, that means they could wash more. This means that we'll need an inequality:

This inequality represents that the total number of cars and trucks they wash will be at least—which means that it is equal to or greater than—than the amount given:

x + y ≥ 26 + 15

Any equation or inequality with two unknowns is not solvable, meaning we need a system of equations:

If they make at least $250, that means that we need to combine the costs of the cars and trucks to make an inequality:

5x + 8y ≥ 250

Now you have your system of equations:

x + y ≥ 26 + 15

5x + 8y ≥ 250

8 0

3 years ago

F(3) for f (x) =1/2(4)^x

Tomtit [17]

Answer:

Step-by-step explanation:

f(x) = 1/2(4)^x

Plug in 3 for x

f(3) = 1/2(4)³

Cube 4.

4³ = 4 x 4 x 4 = 64

f(3) = 1/2(64)

Multiply 64 with 1/2 (or divide by 2)

f(3) = 64/2

f(3) = 32

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2 years ago

20 of the students questioned chose Maths,

Dimas [21]

The number of people that did not choose math or pe is the same amount of people who chose pe

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Write a system that describes the situation:

aleksley [76]

Is the questions asking you to form an equation? or answer the problem?

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