# Mat101

posted by .

5. Which of the following are functions?
The last two problems, i.e., b & c, are multi part relations consider all parts when determining whether or not these relations are functions. Explain your reasoning for a, b, and c.
a. f(x) = x + 3
b. f(x) = 73 if x>2 otherwise f(x) = -1
c. f(x) = 79if x>0 or f(x) = -9 if x<0 or f(x) = 9 or -9 if x = 0

• Mat101 -

To determine if a relation is a function, ask one very important question:
does the relation satisfy the one-to-one condition? That is to say does the relation maps to two values in the codomain (range) from one value in the domain?
Examples:
f(x)=sqrt(x) is not a function because sqrt(x) results in two values.
f(x)=any polynomial with real (i.e. not complex) coefficients is a function, because polynomials satisfy the ono-to-one requirement.

Now can you pick out the functions from the above list, and state why the other(s) is not?

## Similar Questions

1. ### Algebra

Right now we are learning about functions, relations, etc. and I am kind of confused. Here is what I have to answer: Determine whether each of the following is a function. Identify any relations that are not functions. Domain A set …
2. ### pre calc

Find two functions defined implicitly by the given relations: (a) 3x² - y² = 25 (b) y² = x
3. ### MAT 101

5. Which of the following are functions? The last two problems, i.e., b & c, are multi part relations consider all parts when determining whether or not these relations are functions. Explain your reasoning for a, b, and c. a. f(x)
4. ### calculus

when working with composite functions, does fog=gof?
5. ### math

Do relations that are functions always have symmetry?

1. The function f(x) = (2x + 3)^7 is the composition of two functions, g(x) and h(x). Find at least two different pairs of functions g(x) and h(x) such that f(x) = g(h(x)). 2. Give an example of two functions that satisfy the following …