Answer:
Step-by-step explanation:
Several trig identities are involved in the proof of this. This is the order in which they are used.
- cos(2x) = cos²(x) -sin²(x)
- cos²(x) +sin²(x) = 1
- cos(x) = 1/sec(x)
<h3>Proof</h3>
Starting with the left side, we can transform it into the right side.

Answer:
The answer is C.
Step-by-step explanation:
I got this by multiplying the houses by the days it would take to paint to paint one house.
9*4=27
Answer:
2
Step-by-step explanation:
Each time you flip a coin, there is a 50% change of it landing on tails. So half the time you should get a tails.
Half of 4 is 2, so you will likely get 2 tails.
40 boys and 68 girls
let's start with variables and an equation.
boys: x
girls: 2x - 12
and we know that boys and girls make up the class. so let's add the two expressions.
x + 2x - 12 = 108
3x - 12 = 108
+ 12 + 12
3x = 120
x = 40 boys
BUT x is only the number of BOYS in the class. so we have to find girls now. let's plug in our value of x into the girls' equation.
2x - 12 = # of girls
2(40) -12 = # of girls
80 - 12 = # of girls
68 girls
let's check our answer!
68 + 40 does in fact add to 108, therefore our answer is correct.
Alright, since there are 5 numbers, and the mean (or average) is (sum)/(amount of numbers), we have (sum)/5=14. Multiplying both sides by 5, we have the sum being 80. The median of 10 means that in a, b, c, d, e, 10 has to be c and the numbers have to be in ascending order. A and b must be 10 or lower, while d and e must be 10 or higher. Putting some random numbers in, we can have 1, 1, 10, 15, and e. We left e there because the sum needs to be 80, and since 1+1+10+15=27, 80-27=53=e. This, however, would not work if e was less than 10 and we therefore would have needed to make some numbers lower to compensate for this. Our answer is therefore 1, 1, 10, 15, 53