3.1 Functions and Function Notation
What is the difference between a relation and a function?
A relation is a set of ordered pairs; a function is a special kind of relation in which no two ordered pairs have the same first coordinate.
Let f(x) = 9x − 29. What ordered pair in f corresponds to the equation f(x) = 7? Recall y = f(x).
(x,y) = (4,7)
Determine whether the relation represents y as a function of x. 6x + 5y = 30
This relation is a function because there is only one value of y for each input x.
Determine whether the relation represents y as a function of x. x^2 + y^2 = 81
This relation is not a function because there are values of x that correspond to more than one value of y.
Find f(a + 7). f(x) = x2 + 3
f(a + 7) = a^2+14a+52
Given the following function, find h(4). h(t) = t2 − t + 9
h(4) = 21