Answer:
steps below
Step-by-step explanation:
Are you going to solve the value of A or just a proof the equation
cos 2A = cos² A - sin² A
2cos²A-cos2A-1 = 2cos²A - (cos² A - sin² A) - 1 = cos² A + sin² A - 1
2cos²A-cos2A-1 = 1 - 1 = 0
A: 90° or 270° or 450° .....
Answer:

Step-by-step explanation:
The formula for the area of a triangle is given by :
...(1)
Where b is the length of the base and h is the height.
We need to find the value of b from the above formula.
Cross multiplying equation (1) we get :

Now dividing both sides by h. So,

So, the correct option is (D) i.e.
.
Answer:
8,566,379,470 people
Step-by-step explanation:
Let's start simple. In order to find the population increase on January 1, 2006, we need to multiply 6,486,915,022 by 1.4% and add it to 6,486,915,022.
- 6,486,915,022*1.4% = 90,816,810.308
- 90,816,810.308+6,486,915,022 = 6,577,731,832.31 people on January 2006.
Note that the above two steps gives the same answer as 6,486,915,022*1.014.
So we need to do this for each year. 20 years pass between 1/1/2005 and 1/1/2025.
We need to do 6,486,915,022*1.014*1.014*1.014... 20 times.
This is equivalent to
.
Multiplying it out gives us 8566379470.2 = 8,566,379,470 people.
Answer:
6. 550
7. 70
Step-by-step explanation:
6. 16+28 = 44, 44*25 = 1100 divided by 2 = 550
7. 2.5+3+5.5 = 11, 11+3 = 14, 14*10 = 140 divided by 2 = 70