Function Tables and Graphs

Function A function is when each input (x-value) corresponds to exactly one output (y- value) In other words, when you substitute (x) into an equation there is only one possible answer (y)

Let me show you what I mean Lets use the function y = 2x + 5 y = 2(0) + 5 if x = 0 y = 5 xy

Fill in the function table for the function y = 4x – 3 xy

Fill in the function table for the function y = 4x – 3 xy

Fill in the function table for the function y = -3x + 5 xy

Fill in the function table for the function y = -3x + 5 xy

This should be an Olympic sport!

xy

xy

Graphing a Function from a Function Table When given a function you can graph it by creating a function table and plotting the points you generate. You can pick any points for x and substitute them into the function for the output y You should plot at least 5 points to get a good idea of what your graph looks like: 0, two positive numbers, and two negative numbers.

Lets Use the Functions We Worked With Earlier y = 2x + 5 xy

Lets Use the Functions We Worked With Earlier y = 2x + 5 xy

y = 4x – 3 xy

y = 4x – 3 xy Two of our points go way off our graph. It helps to show how steep the slope is.

y = -3x + 5 xy

xy

Closure With a partner, graph the function y = -3x + 3

y = -3x + 3

x y