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: 7,333.32 m3
Step-by-step explanation:
Hi, to answer this question we have to apply the next formula:
Volume of a cone = 1/3 x π x radius^2 x height
Replacing with the values given:
V = 1/3 π (19.3)^2 (18.8) = 7,333.32 m3
The volume of the right circular cone is 7,333.32 cubic meters.
Feel free to ask for more if needed or if you did not understand something.
9514 1404 393
Answer:
(a) {(5, 2), (-4, 2), (3, 6), (0, 4), (-1, 2)}
Step-by-step explanation:
The only relation with no repeated x-values is the first one. The first relation is a function.