Isolate the h in c=25h+350

Find the dimensions of an open rectangular glass tank of volume 4 cubic feet for which the amount of material needed to construc

Rainbow [258]

The base will have the greatest area for a given perimeter if it is square. If the edge of the square base has length x (in feet), then the total material requirement in square feet is
.. m = x^2 +(4/x^2)*(4x)
.. m = x^2 +16/x
This will have a minimum where dm/dx = 0.
.. dm/dx = 2x -16/x^2 = 0
.. x^3 = 8 . . . . . . . . . . . . . . . multiply by x^2/2 and add 8
.. x = 2

The tank is 2 feet square and 1 ft high.

_____
You will note that it is half the height of a cube that has double the volume. This is the generic solution to all minimum cost open-top box problems. Actually, the costs of pairs of opposite sides are equal to each other and to the cost of the base. If material costs are not identical in all directions, that is the more generic solution.

8 0

4 years ago

the right rectangular prism shown has a length of 8ft a width of 2ft and a height of 6ft the dimensions of the prism are doubled

Elan Coil [88]

Answer:

Part 1) The scale factor is $2$

Part 2) The dimensions of the enlarged prism are

a.Length=(8)(2)=16 ft

b.Width=(2)(2)=4 ft

c.Height=(6)(2)=12 ft

Part 3) The surface area of the smaller rectangular prism is 152 ft^{2}

Step-by-step explanation:

we now that

If two figures are similar, then the ratio of its corresponding sides is equal and this ratio is called the scale factor

Part 1)

Find the scale factor

we know that

If the dimensions of the smaller prism are doubled , then the scale factor from the smaller rectangular prism to the larger rectangular prism is equal to $2$

Part 2)

we know that

To find the dimensions of the enlarged figure, multiply the dimensions of the smaller prism by the scale factor

so

Length=(8)(2)=16 ft

Width=(2)(2)=4 ft

Height=(6)(2)=12 ft

Part 3) Find the surface area of the smaller rectangular prism

we know that

The surface area of the rectangular prism is equal to the area of its six rectangular faces

SA=2(8)(2)+2(2)(6)+2(8)(6)=152 ft^{2}

7 0

4 years ago

Algebraic Representation (

Komok [63]

Answer:

sdfm8

Step-by-step explanation:

du9sufmfhmh

6 0

3 years ago

Find the slope of the line that passes through (6, 4) and (4, 5).

Vikki [24]

The answer is m=-1/2

4 0

4 years ago

Read 2 more answers

f) The life of a power transmission tower is exponentially distributed, with mean life 25 years. If three towers, operated indep

Step2247 [10]

Answer:

15.24% probability that at least 2 will still stand after 35 years

Step-by-step explanation:

To solve this question, we need to understand the binomial distribution and the exponential distribution.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

Exponential distribution:

The exponential probability distribution, with mean m, is described by the following equation:

$f(x) = \mu e^{-\mu x}$

In which $\mu = \frac{1}{m}$ is the decay parameter.

The probability that x is lower or equal to a is given by:

$P(X \leq x) = \int\limits^a_0 {f(x)} \, dx$

Which has the following solution:

$P(X \leq x) = 1 - e^{-\mu x}$

The probability of finding a value higher than x is:

$P(X > x) = 1 - P(X \leq x) = 1 - (1 - e^{-\mu x}) = e^{-\mu x}$

Probability of a single tower being standing after 35 years:

Single tower, so exponential.

Mean of 25 years, so $m = 25, \mu = \frac{1}{25} = 0.04$

We have to find $P(X > 35)$

$P(X > 35) = 1 - P(X \leq x) = 1 - (1 - e^{-\mu x}) = e^{-0.04*35} = 0.2466$

What is the probability that at least 2 will still stand after 35 years?

Now binomial.

Each tower has a 0.2466 probability of being standing after 35 years, so $p = 0.2466$

3 towers, so $n = 3$

We have to find:

$P(X \geq 2) = P(X = 2) + P(X = 3)$

In which

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 2) = C_{3,2}.(0.2466)^{2}.(0.7534)^{1} = 0.1374$

$P(X = 3) = C_{3,3}.(0.2466)^{3}.(0.7534)^{0} = 0.0150$

$P(X \geq 2) = P(X = 2) + P(X = 3) = 0.1374 + 0.0150 = 0.1524$

15.24% probability that at least 2 will still stand after 35 years

4 0

3 years ago