I can maybe help, what's the question
1. A relation is a set from x to a set y is called a function if each element of c is related to exactly one element in y. That is,given an element c in c, there is only one element in y that x is related to.
2. You can set up the relation as a table of ordered pairs. Then, text to see if each element in the domain is matched with exactly one element in the range . if so you have a function
3. The domain is the set of all possible x-values which will make the function "work" and will output real y- values .When finding the domain , remember :the denominator (bottom) of a fraction cannot be zero .
4.
Answer:
The value of cos Ф is ± 
Step-by-step explanation:
There are important rules for sin Ф and cos Ф
∵ sin Ф = 
∴ sin²Ф = 
∴ sin²Ф = 
→ By using the third rule above
∵ cos²Ф = 1 - sin²Ф
∴ cos²Ф = 1 -
∴ cos²Ф = 
→ Take square root for both sides
∴ cos Ф = ±
∴ The value of cos Ф is ±
Number of books = 42 / 5/8 (Note 3 1/2 feet = 42 ins.)
= 42 * 8/5 = 336 / 5 = 67.2
67 books will fit on the shelf.
I don’t understand apply to what?
