49.6k views
12 votes
Math: One to One function...help!

Math: One to One function...help!-example-1
User Terra
by
6.3k points

2 Answers

11 votes

Final answer:

A one-to-one function is a type of function where each element in the domain is paired with a unique element in the codomain. It can be determined using the horizontal line test.

Step-by-step explanation:

A one-to-one function, also known as an injective function, is a type of function where each element in the domain is paired with a unique element in the codomain. In other words, no two different elements in the domain can have the same image in the codomain. To determine if a function is one-to-one, you can use the horizontal line test. If a horizontal line intersects the graph of the function at most once, then the function is one-to-one.

For example, the function f(x) = x^2 is not one-to-one because for every positive value of x, there are two different values of f(x) (x^2 and (-x)^2). On the other hand, the function f(x) = 2x + 3 is one-to-one because for every unique value of x, there is a unique value of f(x).

User Joshtkling
by
6.5k points
4 votes

A one-to-one function has an inverse. The inverse is another function that undoes the action of the first one, so if we evaluate a function
f at some point
x to get the number
f(x), evaluating the inverse at
f(x) will recover the original input
x. In other words,


f^(-1)(f(x)) = x

The process works in the opposite direction, too:


f\left(f^(-1)(x)\right) = x

From the given definition of
g, we have
g(-4) = 3, so taking inverses on both sides, we find


g(-4) = 3 \implies g^(-1)(g(-4)) = g^(-1)(3) \implies \boxed{g^(-1)(3) = -4}

Given
h(x)=2x-13, evaluating
h at its inverse will recover
x, so that


h\left(h^(-1)(x)\right) = x \implies 2h^(-1)(x) - 13 = x \implies \boxed{h^(-1)(x) = \frac{x+13}2}


(h\circ h^(-1))(x) is another way of writing the compound function
h\left(h^(-1)(x)\right). As already discussed, this reduces to
x, so


\boxed{\left(h\circ h^(-1)\right)(-9) = -9}

User Igonato
by
5.9k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.