cos(3x) = cos(2x+x)
= cos(2x) cos (x) -sin(2x)sin(x)








Answer: Choice C) y = 30/x
Inverse variation equations are of the form y = k/x. In this case, k = 30. We can rearrange the format to get x*y = k after multiplying both sides by x. So y = 30/x can be turned into x*y = 30.
9514 1404 393
Answer:
A. √13
Step-by-step explanation:
You can make an educated guess and come to the right conclusion.
The triangle is nearly an equilateral triangle. A triangle with two sides 3 and an angle of 60° would have a third side of 3. A triangle with two sides of 4 and an angle of 60° would have a third side of 4.
So, the third side must be between 3 and 4. Here is an evaluation of the answer choices:
__
A -- between 3 and 4, the correct choice
B -- 3, too short
C -- 1.73, too short
D -- more than 4, too long
__
The question can be answered using your triangle solver app on your calculator, or using the Law of Cosines.
c = √(a^2 +b^2 -2ab·cos(C))
c = √(3^2 +4^2 -2·3·4·(1/2)) = √(9 +16 -12)
c = √13 . . . . . length of the side opposite the 60° angle
Answer:
top row on 9 page; 9) 53/5 10) 26/4 11) 37/4
bottom row on 9 page; 9) 8 and 1/7 10) 6 and 3/4 11) 1 and 1/3
top row on 3 page; 3) 2 and 2/7 4) 5 and 3/4 5) 8 and 1/10
bottom row on 3 page; 3) 4/3 4) 3/2 5) 12/5
top row on 12 page; 12) 21/10 13) 62/6 14) 57/6
bottom row on 12 page; 12) 1 and 9/10 13) 10 and 1/2 14) 3 and 3/8
Step-by-step explanation:
You never specified if these had to be simplified or turned into a fraction, so I just simplified them. That's about it.
I hope this helps :)