Answer:
All polygons have straight lines
Step-by-step explanation:
Let's start from what we know.

Note that:

(sign of last term will be + when n is even and - when n is odd).
Sum is finite so we can split it into two sums, first

with only positive trems (squares of even numbers) and second

with negative (squares of odd numbers). So:

And now the proof.
1) n is even.
In this case, both

and

have

terms. For example if n=8 then:

Generally, there will be:

Now, calculate our sum:



So in this case we prove, that:

2) n is odd.
Here,

has more terms than

. For example if n=7 then:

So there is

terms in

,

terms in

and:

Now, we can calculate our sum:




We consider all possible n so we prove that:
Answer:
The correct option is B.
Step-by-step explanation:
It is given that the surface area of an oil spill gets 131% larger every day, represented by the function
Where x is number of days.
On the first day, it covered an area of 21 square meters. It means the initial area is 21 square meters.
The function is defined as
Where is initial value and b is growth factor.
It means the function of new area is the product of initial area and increasing area function. The required function is
Therefore option B is correct.
Answer:
2
Step-by-step explanation: