Answer:
A function is a relation that maps inputs from a set called the domain, into outputs from a set called the range.
Such that each input can be mapped into only one output.
So for example, if we have a relation that maps the input 2 into two different values:
f(2) = 4
f(2) = 8
Then this is not a function.
In the case of the problem, we have a student as the input, and the hair color as the output.
So we will have something like:
f(student) = blond
And if this student decides to change his/her hair color to red?
Then the function becomes:
f(student) = red
So for the same input, we had two different outputs, which means that this is not a function.
We also could have the case where a given student has two colors (Californian for example)
Where again, we would see two different outputs for one single input.
Answer:
B. 88.8
Step-by-step explanation:
let x represent class y
(x+71.2)/2=80 multiply each side by 2
x+71.2=160 subtract 71.2 by both sides
x=88.8
or
trial an error
replace x with each of the numbers and see if it plugs in.
example:
(80.5+71.2)/2=80
151.7/2=80
75.85=80?
false. incorrect
another example:
(88.8+71.2)/2=80
160/2=80
80=80?
true. correct
Answer:
The ratios are both identical (3/5 and 3/5).
Step-by-step explanation:
sin x° is equivalent to O/H, or the opposite/hypotenuse sides of the triangle. Therefore:
sin x° = 3/5.
cos y° is equivalent to A/H, or the adjacent/hypotenuse sides of the triangle.
cos y° = 3/5.

The ratios are identical.
Answer:3⁴ and 81¹
Step-by-step explanation:
3⁹= 19683
3⁴= 81
-9²= -81
9⁹= 387,420,489
81¹= 81