Answer:
D
Step-by-step explanation:
Using cosine formula, we have
Answer:
The area of the Iris is 4 times greater.
Step-by-step explanation:
Firstly, we have to realize that we cannot solve this problem without knowing the radius of the iris. because from the information given, the radius of the iris could well be the size of the galaxy and contract from width of 4mm to 2mm and we wouldn't know!
The average radius of the iris is 6mm, so we take this value.
Now, initially the width of the iris is 4mm, that means the radius of the pupil is:

Therefore it's area
is:

When the iris contracts to 2mm, the radius of the pupil becomes:

Then it's area is
:

To find how many times greater this final area is than the initial area, we just divide it by the initial area:

This is 4 times greater than the initial area.
That's a question about percentage.
One way to represent percentage is using decimal number. In this way, 1 is equivalent to 100% and the other less percentages using numbers between 0 and 1.
Examples:
- 90% is equivalent to 0,90.
- 5% is equivalent to 0.05. It's not 0.5 because 0.5 is equivalent to 50%.
- 13.17% is equivalent to 0.1317.
- 245% is equivalent to 2.45.
If we want to know the percentage of a number, we should multiplacate the number by the porcentage in the decimal number form.
Examples:
- 55.90% of 200 is equal to:

- 360% of 88 is equal to:

In our problem, we have a phone with a increase of 7%. To solve that, it's important to perceive that $230 is equal to 100% and with a increase of 7%, we will pay 107%.
107% in the decimal number form is 1.07. With that information, we should multiplicate 1.07 by the original value and we will find the answer.
We know that
, therefore, the total cost of the phone after tax is $246.1.
I hope I've helped. :D
Enjoy your studies. \o/
Answer:

Step-by-step explanation:
The given sequence is
-12,-16,-20...
The first term of this sequence is
.
The common difference is


The nth term of this arithmetic sequence is;

We substitute the values for the first term and the common difference to obtain;

Answer:
math a app good luck with the question