Which of the following statements are true regarding functions? Check all that apply.
A. A function is a relation in which each value of the input variable is
paired with exactly one value of the output variable.
B. The vertical line test may be used to determine whether a function is one-to-one.
c. The horizontal line test may be used to determine whether a function is one-to-one.
D. A sequence is a function whose domain is the set of real numbers.