What is a Cubic Function?
A cubic function is a function in the form
Note that the degree of this function (the highest exponent) is 3; hence why it is called a cubic function! Cubic functions have a very distinctive, curvy graph.
How to Use Cubic Functions?
The standard form of a cubic function is
To graph a cubic function, choose several x values, plug them in, and find the y value at those points. Then plot those points and connect them with a line. All cubic functions will have a distinctive curvy shape (see example graph above).
As with quadratics, we can talk about the roots of the function (where it crosses the x-axis), as well as the y-intercept (where it crosses the y-axis).
Sample Math Problems
Problem
Which of the following are cubic functions?
(A)
(B)
