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2 years ago

A function that is injective but not surjective

1 answer:

5 0

An example of an injective function R→R that is not surjective is h(x)=ex. This "hits" all of the positive reals, but misses zero and all of the negative reals. But the key point is the the definitions of injective and surjective depend almost completely on the choice of range and domain.

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a triangle has an area of 38.4cm.the height of the triangle is 12.8cm.what is the length of the base of the triangle

Solnce55 [7]

Answer: 6 cm

Step-by-step explanation:

Use equation for area of triangle

A=a*h/2

a*h=2A

a=2A/h

where a represents base of triangle

h represents height of triangle.

h=12.8 cm

A=38.4 cm²

a=2A/h=2*38.4 cm²/12.8 cm=76.8cm²/12.8cm= 6 cm

4 0

2 years ago

A wild animal generally stays at least x mi from the edge of a forest. For a rectangular forest preserve that is 2 mi

Butoxors [25]

Answer:

$Area = 4x^2 - 14x + 10$

Step-by-step explanation:

<em>See Attachment for Complete Question</em>

Given

$Width = 5mi$ --- For the forest

$Length = 2mi$ -- --- For the forest

Required

Determine the area of the habitat

Since the distance between the animal's habitat is x mi on both sides;

The length and width of the habitat is:

$Width = 5 - (x + x)$

$Width = 5 - 2x$

$Height = 2 - (x +x)$

$Height = 2 - 2x$

The area is then calculated as follows;

$Area = Width * Height$

$Area = (5 - 2x) * (2 - 2x)$

Expand

$Area = 5(2 - 2x) -2x(2 - 2x)$

Open Brackets

$Area = 10 - 10x - 4x + 4x^2$

$Area = 10 - 14x + 4x^2$

Reorder

$Area = 4x^2 - 14x + 10$

Hence; the required polynomial for the habitat area is:

$Area = 4x^2 - 14x + 10$

3 0

2 years ago

Jenny multiplies the square root of her favorite positive integer by $\sqrt{2}$. Her product is an integer. a) Name three number

Dmitry [639]

Answer:

Part a) $2,50,18$

Part b) When Jenny divides the square root of her favorite positive integer by $\sqrt{2}$ , she gets an integer

Step-by-step explanation:

Let

x-------> the favorite positive integer

Part a)

1) For $x=2$

$\sqrt{2}*\sqrt{2}=\sqrt{4}=2$ -----> the product is an integer

The number $x=2$ could be Jenny favorite positive integer

2) For $x=50$

$\sqrt{50}*\sqrt{2}=\sqrt{100}=10$ -----> the product is an integer

The number $x=50$ could be Jenny favorite positive integer

3) For $x=18$

$\sqrt{18}*\sqrt{2}=\sqrt{36}=6$ -----> the product is an integer

The number $x=18$ could be Jenny favorite positive integer

Part B)

1) For $x=2$

$\sqrt{2}/\sqrt{2}=\sqrt{1}=1$ -----> the result is an integer

2) For $x=50$

$\sqrt{50}/\sqrt{2}=\sqrt{25}=5$ -----> the result is an integer

3) For $x=18$

$\sqrt{18}/\sqrt{2}=\sqrt{9}=3$ -----> the result is an integer

Therefore

When Jenny divides the square root of her favorite positive integer by $\sqrt{2}$ , she gets an integer

4 0

2 years ago

What is 10 times 7 thousands in unit form

Irina18 [472]

10 times 7 is 70.
So, it is 70 thousands.
Or in other words, seven ten-thousands.
or just write it normally: 10*7*1000=70000=seventy thousand
Wee!

7 0

2 years ago

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It takes 5 carpenters 5 hours to make 5 chairs. How long would it take 100 carpenters to make 100 chairs?

Elza [17]

I hour because, one of the 5 carpenters built one chair in one hour, so one of the 100 carpenters would build one chair in one hour, there are only 95 more carpenters, nothing else different.
Hope I helped!

7 0

2 years ago

Read 2 more answers