All categories

3 years ago

How do I show that V=28x^2 - 2x^3 ??

Mathematics

1 answer:

VARVARA [1.3K]3 years ago

7 0

4y + 8x = 112

V = x*x*y= x^2y

y + 2 x = 28

y = 28 - 2x

V = x^2 (28-2x) = 28 x^2 - 2 x^3

You might be interested in

What is 879 minus 690?

malfutka [58]

Answer:

189

Step-by-step explanation:

6 0

4 years ago

A 1.5-mm layer of paint is applied to one side of the following surface. Find the approximate volume of paint needed. Assume tha

Mariulka [41]

Answer:

V = 63π / 200 m^3

Step-by-step explanation:

Given:

- The function y = f(x) is revolved around the x-axis over the interval [1,6] to form a spherical surface:

y = √(42*x - x^2)

- The surface is coated with paint with uniform layer thickness t = 1.5 mm

Find:

The volume of paint needed

Solution:

- Let f be a non-negative function with a continuous first derivative on the interval [1,6]. The Area of surface generated when y = f(x) is revolved around x-axis over the interval [1,6] is:

$S = 2*\pi \int\limits^a_b { [f(x)*\sqrt{1 + f'(x)^2} }] \, dx$

- The derivative of the function f'(x) is as follows:

$f'(x) = \frac{21-x}{\sqrt{42x-x^2} }$

- The square of derivative of f(x) is:

$f'(x)^2 = \frac{(21-x)^2}{42x-x^2 }$

- Now use the surface area formula:

$S = 2*\pi \int\limits^6_1 { [\sqrt{42x-x^2} *\sqrt{1 + \frac{(21-x)^2}{42x-x^2 } }] \, dx\\\\S = 2*\pi \int\limits^6_1 { [\sqrt{42x-x^2+(21-x)^2} }] \, dx\\\\S = 2*\pi \int\limits^6_1 { [\sqrt{42x-x^2+441-42x+x^2} }] \, dx\\\\S = 2*\pi \int\limits^6_1 { [\sqrt{441} }] \, dx\\S = 2*\pi \int\limits^6_1 { 21} \, dx\\\\S = 42*\pi \int\limits^6_1 { dx} \,\\\\S = 42*\pi [ 6 - 1 ]\\\\S = 42*5*\pi \\\\S = 210\pi$

- The Volume of the pain coating is:

V = S*t

V = 210*π*3/2000

V = 63π / 200 m^3

8 0

4 years ago

Read 2 more answers

At a farmers market strawberries cost $1.60 per pint, blueberries cost $2.30 per pint. A shopper bought twice as many pints of s

djverab [1.8K]

4 pints of strawberries and 2 pints of blueberries are bought

Solution:

Let "a" be the pints of strawberries bought

Let "b" be the pints of blueberries cost

Cost per pint of strawberry = $ 1.60

Cost per pint of blueberry = $ 2.30

A shopper bought twice as many pints of strawberries as pints of blueberries

Therefore,

a = 2b --------- eqn 1

They spent a total of $11.00. Therefore we frame a equation as:

pints of strawberries bought x Cost per pint of strawberry + pints of blueberries cost x Cost per pint of blueberry = 11

$a \times 1.60 + b \times 2.30 = 11$

1.6a + 2.3b = 11 --------- eqn 2

Substitute eqn 1 in eqn 2

1.6(2b) + 2.3b = 11

3.2b + 2.3b = 11

5.5b = 11

Divide both sides by 11

b = 2

Substitute b = 2 in eqn 1

a = 2(2)

a = 4

Thus 4 pints of strawberries and 2 pints of blueberries are bought

5 0

3 years ago

Reflect (-1, 5) over the x-axis.

Deffense [45]

Answer:

(-1,-3)

Step-by-step explanation:

7 0

3 years ago

ASAP i need help with this. I will give you brainlist

Tju [1.3M]

Part A 60x3=180
5x30=150
150+180=330 sry only doing part A

3 0

4 years ago