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3 years ago

Given cos A=

Mathematics

1 answer:

AURORKA [14]3 years ago

8 0

Answer:

ndkndksndssjsjsjsjsjs nsj

Step-by-step explanation:

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A right square pyramid has a base area of 300 square inches and a height of 3 inches

Dominik [7]

Answer:

Step-by-step explanation:

Height: 3 inches

Base area: 300

5 0

3 years ago

A rectangular storage container with an open top is to have a volume of 10 m3 . then length of its base is twice the width. mate

katrin [286]

Answer:

The cost of materials for the cheapest such container is $163.54.

Step-by-step explanation:

A rectangular storage container with an open top is to have a volume of 10 m³.

The volume of the rectangle is

$\text{Volume} =\text{Length} \times \text{Width} \times \text{Height}$

Length of its base is twice the width.

Let Width be 'w'.

Length is l=2w.

Height be 'h'.

$10 =2w\times w\times h$

$10=2w^2h$

The height in terms of width is represented as,

$h=\frac{10}{2w^2}$

$h=\frac{5}{w^2}$

According to question,

The cost is 10 times the area of the base and 6 times the total area of the sides.

i.e. Cost is given by,

$C=10(L\times W)+6(2\times L\times H+2\times W\times H)$

$C=10(2w\times w)+6(2\times 2w\times \frac{5}{w^2}+2\times w\times \frac{5}{w^2})$

$C=20w^2+\frac{120}{w}+\frac{60}{w}$

$C(w)=20w^2+\frac{180}{w}$

To get the minimum value,

Differentiate the cost w.r.t 'w',

$C'(w)=20\frac{d(w^2)}{dw}+180\frac{d(w^{-1})}{dw}$

$C'(w)=20\times 2w-180 w^{-2}$

$C'(w)=40w-\frac{180}{w^2}$

To find critical points put derivate =0,

$40w-\frac{180}{w^2}=0$

$40w=\frac{180}{w^2}$

$w^3=\frac{180}{40}$

$w=\sqrt[3]{4.5}$

$w=1.65$

We find the second derivative to minimize,

$C''(w)=40\frac{d(w)}{dw}-180\frac{d(w^{-2})}{dw}$

$C''(w)=40+360(w^{-3})$

$C''(w)>0$

As $C''(w)>0$ it is the minimum cost.

The cost is minimum at w=1.65.

Substitute the values in the cost function,

$C(1.65)=20(1.65)^2+\frac{180}{1.65}$

$C(1.65)=54.45+109.09$

$C(1.65)=163.54$

Therefore, the cost of materials for the cheapest such container is $163.54.

7 0

3 years ago

7x-9+3x=2x+18-x submit i want an answer please

oksano4ka [1.4K]

Answer:

x = 3

Step-by-step explanation:

7x - 9 + 3x = 2x + 18 - x

10x - 9 = x + 18

10x - x = 18 + 9

9x = 27

x = 3

6 0

3 years ago

Read 2 more answers

PLEASE HELPP! The diameter of a decorated plate is 20 centimeters. There is a flower painted every 15.7 centimeters around the e

kirill115 [55]

Answer:

4 flowers

Step-by-step explanation:

First we need to calculate the circumference of the plate.

C = πd

Given

diameter d = 20cm

C = 3.14(20)

C = 62.8 cm

If there is a flower painted every 15.7 centimeters around the edge of the plate, the amount of flower on the plate will be;

Number of flower = Circumference of the plate/length of flower

Amount of flower = 62.8/15.7

Amount of flower = 4

Hence there are 4 flowers painted on the plate

4 0

3 years ago

Read 2 more answers

In a taste test, each sample serving of a new drink is about 50 milliliters The drink comes in a 1 liter

expeople1 [14]

Answer:

Step-by-step explanation:

it is 25 $25+125=50$

7 0

3 years ago