Cos(2x) = cos^2(x) - sin^2(x) - cos(x)
but sin^2(x) = 1 - cos^2(x)
cos(2x) - cos(x) = cos^2(x) - (1 - cos^2(x) ) - cos(x)
cos(2x) - cos(x) = cos^2(x) - 1 + cos^2(x) - cos(x)
cos(2x) - cos(x) = 2cos^2(x) - 1 - cos(x)
cos(2x) - cos(x) = (2cos(x) + 1)(cos(x) - 1)
I think this is what you have asked for.
Answer:
79
Step-by-step explanation:
The area of a circle is pi*radius^2; the radius of this circle is 10 (20/2=10). Our area is then 100pi or ~314 square feet. A 2x2 square takes up 4 feet. 314/4 is equal to 78.5, or when rounded, 79
3.33 repeating. if you look at it it's 2.70 what I would do is take away the zero for a minute and see how many times 9 goes into 27
Answer:
The average annual growth rate of a certain country's population for 1950, 1988, and 2010 are 2.398, 0.9985 and 0.2236 respectively.
Step-by-step explanation:
The given equation is

Where Y is the annual growth rate of a certain country's population and x is the number of years after 1900.
Difference between 1950 and 1900 is 50.
Put x=50 in the given equation.


Therefore the estimated average annual growth rate of the country's population for 1950 is 2.398.
Difference between 1988 and 1900 is 88.
Put x=88 in the given equation.


Therefore the estimated average annual growth rate of the country's population for 1988 is 0.9985.
Difference between 2010 and 1900 is 110.
Put x=110 in the given equation.


Therefore the estimated average annual growth rate of the country's population for 2010 is 0.2236.
Answer:
It’s 4
Step-by-step explanation: