Polynomial: Difference between revisions

From Objective Mathematics
Jump to navigation Jump to search
Line 6: Line 6:
Every [[linear transformation]] is uniquely associated to a polynomial called its characteristic polynomial.  
Every [[linear transformation]] is uniquely associated to a polynomial called its characteristic polynomial.  


A computer program consisting of some number of <code>for</code> loops (and no recursion or <code>goto</code>s or other loops), where each <code>for</code> loop runs exactly <math>n</math> times, will take a number of steps to run which is given by some polynomial in <math>n</math>. In fact, any polynomial at all can be realized in this way.
A computer program consisting of some number of <code>for</code> loops (and no recursion or <code>goto</code>s or other loops), where each <code>for</code> loop runs exactly <math>n</math> times, will take a number of steps to run which is given by some polynomial in <math>n</math>. In fact, any polynomial with <math>\mathbb{Z}_{\geq 0}</math> coefficients can be realized in this way.


Some generating functions in combinatorics or representation theory (those which truncate after a finite number of powers).  
Some generating functions in combinatorics or representation theory (those which truncate after a finite number of powers).  

Revision as of 20:03, 18 November 2024

A polynomial is any function which obtains its result solely by some combination of: multiplying its inputs together, adding them together, or rescaling them.

Examples

The volume of a cube is a polynomial in its side length.

Every linear transformation is uniquely associated to a polynomial called its characteristic polynomial.

A computer program consisting of some number of for loops (and no recursion or gotos or other loops), where each for loop runs exactly times, will take a number of steps to run which is given by some polynomial in . In fact, any polynomial with coefficients can be realized in this way.

Some generating functions in combinatorics or representation theory (those which truncate after a finite number of powers).

A truncated Taylor series approximation to anything. Tangent line to a curve at a point, tangent conic to a curve at a point, tangent cubic to a curve at a point, etc.

Piecewise polynomial functions (a type of spline) are used in computer graphics to make things look smooth.

Rational functions [TODO move to its own page]

There are many examples of useful, practical rational functions that arise as ratios between square distances in trigonometry. See Norman Wildberger's book.