Answer:
Step-by-step explanation:
As the statement is ‘‘if and only if’’ we need to prove two implications
is surjective implies there exists a function
such that
.- If there exists a function
such that
, then
is surjective
Let us start by the first implication.
Our hypothesis is that the function
is surjective. From this we know that for every
there exist, at least, one
such that
.
Now, define the sets
. Notice that the set
is the pre-image of the element
. Also, from the fact that
is a function we deduce that
, and because
the sets
are no empty.
From each set
choose only one element
, and notice that
.
So, we can define the function
as
. It is no difficult to conclude that
. With this we have that
, and the prove is complete.
Now, let us prove the second implication.
We have that there exists a function
such that
.
Take an element
, then
. Now, write
and notice that
. Also, with this we have that
.
So, for every element
we have found that an element
(recall that
) such that
, which is equivalent to the fact that
is surjective. Therefore, the prove is complete.
Answer:
The fixed costs per day for the factory is $10,000 and marginal cost of one refrigerator for $500
Step-by-step explanation:
Let
Cost per refrigerator (marginal cost) = r
Fixed costs per day for the factory = f
Total cost = variable cost + fixed cost
Monday
25,000 = 30r + f
Tuesday
30,000 = 40r + f
Using Monday,
f = 25000 -30r
Substitute f = 25000 - 30r into Tuesday
30,000 = 40r + f
30,000 = 40r + (25,000 -30r)
30,000 = 40r + 25,000 - 30r
Collect like terms
30,000 - 25,000 = 40r - 30r
5,000 = 10r
Divide both sides by 10
r = 5,000 / 10
= 500
r = $500
Substitute r= 500 into Monday equation
f = 25,000 -30r
= 25,000 - 30(500)
= 25,000 - 15,000
= 10,000
f = $10,000
Therefore, the fixed costs per day for the factory is $10,000 and marginal cost of one refrigerator for $500
Answer:
6x^2*(x+4)
Step-by-step explanation:
hope this helps! :)
The multiplication of the expression (x² + 3x + 2) (2x² + 3x + 1) is 2x⁴ + 9x³ + 14x² + 9x + 2
<h3>Multiplication</h3>
(x² + 3x + 2) (2x² + 3x + 1)
= 2x⁴ + 3x³ + x² + 6x³ + 9x² + 3x + 4x² + 6x + 2
= 2x⁴ + 3x³ + 6x³ + x² + 9x² + 4x² + 3x + 6x + 2
= 2x⁴ + 9x³ + 14x² + 9x + 2
Learn more about multiplication:
brainly.com/question/10873737
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