Polynomial Modeling
Polynomial functions can be degree 0 (constant), 1 (linear), 2 (quadratic), 3 (cubic) and so on.
This principal confirms that any two points determine a unique line. Three points that are not on a line determine a unique parabola. Four points that are not on a line or a parabola determine a unique cubic and so forth.
Using Your Calculator
Go to stat edit and plug in the coordinates
Afterwards, test out LinReg, CubicReg, QuadReg, and QuartReg
Which ever one has an R2 that is closest to the number 1, is your best model
Practice Problems
1.) Write a polynomial function whose graph passes through (0,5), (2,10), and (1,4). .Use a regression to check your answer.
2.) Find a linear, a quadratic, and a cubic model for the data. Which model best fits the data?
x: 3 8 15 21
y: 7 11 26 44
3.) Use CUBIREG to model the data below. Then use the model to estimate the population in 2008. Let x be the number of years after 2000.
x: 2004 2007 2009 2010
y: 457 910 1244 1315
