Recall the double angle identity for cosine:

It follows that

Since 0° < 22° < 90°, we know that sin(22°) must be positive, so csc(22°) is also positive. Let x = 22°; then the closest answer would be C,

but the problem is that none of these claims are true; cot(32°) ≠ 4/3, cos(44°) ≠ 5/13, and csc(22°) ≠ √13/2...
As this is already in its simplest form, I believe the only other expression is 4*X +9
Number of ways to select 3 books from 13 books for adoption is 286 .
<u>Step-by-step explanation:</u>
A Permutation is an ordered Combination. When the order does matter it is a Permutation. There are basically two types of permutation:
- Repetition is Allowed: such as the lock above. It could be "333".
- No Repetition: for example the first three people in a running race. You can't be first and second.
Formula is given by:
, where n is the number of things to choose from, and we choose r of them, no repetitions, order matters. Here , n=13 , r=3.
⇒ 
⇒ 
⇒ 
⇒ 
⇒ 
∴ Number of ways to select 3 books from 13 books for adoption is 286 .
Answer:
Step-by-step explanation:
17) B. They are adding 2 to both sides.
18) A. A segment is equal to itself.
19) D. They are multiplying both sides by 2.
20) C. They are simply swapping the left and right hand sides of the equation
Answer:
=8x^3+27
Step-by-step explanation:
First you are going to multply 2x by all of the other numbers in the 2nd parentheses, then do the same with 3. By doing this you should get and answer then combine like terms.