What is a function?

1 Answer
Mar 25, 2018

Answer:

A function is a set of ordered pairs (points) formed from a defining equation, where, for each #x#-value there is only one #y#-value.

Explanation:

#x-------> y# represents a function

This means that you can choose an #x#-value and plug it into an equation, usually given as:

#y= ....." " or" " f(x)= .....#

This will give you a #y#-value.

In a function there will be only ONE possible answer for #y#.

If you find you have a choice, then the equation does not represent a function.

The following are functions:

#y=-3#

#y=3x-5#

#y = 2x^2-3x+1#

#(1,2), (2,2), (3,2),(4,2)#

The following are NOT functions:

#x= 3#

#y=+-sqrt(x+20)#